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Return a list of unique items in the list provided, preserving the order in which they are found.
def _unique_with_order_preserved(items): """ Return a list of unique items in the list provided, preserving the order in which they are found. """ new_items = [] for item in items: if item not in new_items: new_items.append(item) return new_items
Return a correlation matrix between the pixel coordinates and the high level world coordinates, along with the list of high level world coordinate classes. The shape of the matrix is ``(n_world, n_pix)``, where ``n_world`` is the number of high level world coordinates.
def _pixel_to_world_correlation_matrix(wcs): """ Return a correlation matrix between the pixel coordinates and the high level world coordinates, along with the list of high level world coordinate classes. The shape of the matrix is ``(n_world, n_pix)``, where ``n_world`` is the number of high level world coordinates. """ # We basically want to collapse the world dimensions together that are # combined into the same high-level objects. # Get the following in advance as getting these properties can be expensive all_components = wcs.low_level_wcs.world_axis_object_components all_classes = wcs.low_level_wcs.world_axis_object_classes axis_correlation_matrix = wcs.low_level_wcs.axis_correlation_matrix components = _unique_with_order_preserved([c[0] for c in all_components]) matrix = np.zeros((len(components), wcs.pixel_n_dim), dtype=bool) for iworld in range(wcs.world_n_dim): iworld_unique = components.index(all_components[iworld][0]) matrix[iworld_unique] |= axis_correlation_matrix[iworld] classes = [all_classes[component][0] for component in components] return matrix, classes
Correlation matrix between the input and output pixel coordinates for a pixel -> world -> pixel transformation specified by two WCS instances. The first WCS specified is the one used for the pixel -> world transformation and the second WCS specified is the one used for the world -> pixel transformation. The shape of the matrix is ``(n_pixel_out, n_pixel_in)``.
def _pixel_to_pixel_correlation_matrix(wcs_in, wcs_out): """ Correlation matrix between the input and output pixel coordinates for a pixel -> world -> pixel transformation specified by two WCS instances. The first WCS specified is the one used for the pixel -> world transformation and the second WCS specified is the one used for the world -> pixel transformation. The shape of the matrix is ``(n_pixel_out, n_pixel_in)``. """ matrix1, classes1 = _pixel_to_world_correlation_matrix(wcs_in) matrix2, classes2 = _pixel_to_world_correlation_matrix(wcs_out) if len(classes1) != len(classes2): raise ValueError("The two WCS return a different number of world coordinates") # Check if classes match uniquely unique_match = True mapping = [] for class1 in classes1: matches = classes2.count(class1) if matches == 0: raise ValueError("The world coordinate types of the two WCS do not match") elif matches > 1: unique_match = False break else: mapping.append(classes2.index(class1)) if unique_match: # Classes are unique, so we need to re-order matrix2 along the world # axis using the mapping we found above. matrix2 = matrix2[mapping] elif classes1 != classes2: raise ValueError( "World coordinate order doesn't match and automatic matching is ambiguous" ) matrix = np.matmul(matrix2.T, matrix1) return matrix
Given an axis correlation matrix from a WCS object, return information about the individual WCS that can be split out. The output is a list of tuples, where each tuple contains a list of pixel dimensions and a list of world dimensions that can be extracted to form a new WCS. For example, in the case of a spectral cube with the first two world coordinates being the celestial coordinates and the third coordinate being an uncorrelated spectral axis, the matrix would look like:: array([[ True, True, False], [ True, True, False], [False, False, True]]) and this function will return ``[([0, 1], [0, 1]), ([2], [2])]``.
def _split_matrix(matrix): """ Given an axis correlation matrix from a WCS object, return information about the individual WCS that can be split out. The output is a list of tuples, where each tuple contains a list of pixel dimensions and a list of world dimensions that can be extracted to form a new WCS. For example, in the case of a spectral cube with the first two world coordinates being the celestial coordinates and the third coordinate being an uncorrelated spectral axis, the matrix would look like:: array([[ True, True, False], [ True, True, False], [False, False, True]]) and this function will return ``[([0, 1], [0, 1]), ([2], [2])]``. """ pixel_used = [] split_info = [] for ipix in range(matrix.shape[1]): if ipix in pixel_used: continue pixel_include = np.zeros(matrix.shape[1], dtype=bool) pixel_include[ipix] = True n_pix_prev, n_pix = 0, 1 while n_pix > n_pix_prev: world_include = matrix[:, pixel_include].any(axis=1) pixel_include = matrix[world_include, :].any(axis=0) n_pix_prev, n_pix = n_pix, np.sum(pixel_include) pixel_indices = list(np.nonzero(pixel_include)[0]) world_indices = list(np.nonzero(world_include)[0]) pixel_used.extend(pixel_indices) split_info.append((pixel_indices, world_indices)) return split_info
Transform pixel coordinates in a dataset with a WCS to pixel coordinates in another dataset with a different WCS. This function is designed to efficiently deal with input pixel arrays that are broadcasted views of smaller arrays, and is compatible with any APE14-compliant WCS. Parameters ---------- wcs_in : `~astropy.wcs.wcsapi.BaseHighLevelWCS` A WCS object for the original dataset which complies with the high-level shared APE 14 WCS API. wcs_out : `~astropy.wcs.wcsapi.BaseHighLevelWCS` A WCS object for the target dataset which complies with the high-level shared APE 14 WCS API. *inputs : Scalars or arrays giving the pixel coordinates to transform.
def pixel_to_pixel(wcs_in, wcs_out, *inputs): """ Transform pixel coordinates in a dataset with a WCS to pixel coordinates in another dataset with a different WCS. This function is designed to efficiently deal with input pixel arrays that are broadcasted views of smaller arrays, and is compatible with any APE14-compliant WCS. Parameters ---------- wcs_in : `~astropy.wcs.wcsapi.BaseHighLevelWCS` A WCS object for the original dataset which complies with the high-level shared APE 14 WCS API. wcs_out : `~astropy.wcs.wcsapi.BaseHighLevelWCS` A WCS object for the target dataset which complies with the high-level shared APE 14 WCS API. *inputs : Scalars or arrays giving the pixel coordinates to transform. """ # Shortcut for scalars if np.isscalar(inputs[0]): world_outputs = wcs_in.pixel_to_world(*inputs) if not isinstance(world_outputs, (tuple, list)): world_outputs = (world_outputs,) return wcs_out.world_to_pixel(*world_outputs) # Remember original shape original_shape = inputs[0].shape matrix = _pixel_to_pixel_correlation_matrix(wcs_in, wcs_out) split_info = _split_matrix(matrix) outputs = [None] * wcs_out.pixel_n_dim for pixel_in_indices, pixel_out_indices in split_info: pixel_inputs = [] for ipix in range(wcs_in.pixel_n_dim): if ipix in pixel_in_indices: pixel_inputs.append(unbroadcast(inputs[ipix])) else: pixel_inputs.append(inputs[ipix].flat[0]) pixel_inputs = np.broadcast_arrays(*pixel_inputs) world_outputs = wcs_in.pixel_to_world(*pixel_inputs) if not isinstance(world_outputs, (tuple, list)): world_outputs = (world_outputs,) pixel_outputs = wcs_out.world_to_pixel(*world_outputs) if wcs_out.pixel_n_dim == 1: pixel_outputs = (pixel_outputs,) for ipix in range(wcs_out.pixel_n_dim): if ipix in pixel_out_indices: outputs[ipix] = np.broadcast_to(pixel_outputs[ipix], original_shape) return outputs[0] if wcs_out.pixel_n_dim == 1 else outputs
Return a matrix of shape ``(world_n_dim, pixel_n_dim)`` where each entry ``[i, j]`` is the partial derivative d(world_i)/d(pixel_j) at the requested pixel position. Parameters ---------- wcs : `~astropy.wcs.WCS` The WCS transformation to evaluate the derivatives for. *pixel : float The scalar pixel coordinates at which to evaluate the derivatives. normalize_by_world : bool If `True`, the matrix is normalized so that for each world entry the derivatives add up to 1.
def local_partial_pixel_derivatives(wcs, *pixel, normalize_by_world=False): """ Return a matrix of shape ``(world_n_dim, pixel_n_dim)`` where each entry ``[i, j]`` is the partial derivative d(world_i)/d(pixel_j) at the requested pixel position. Parameters ---------- wcs : `~astropy.wcs.WCS` The WCS transformation to evaluate the derivatives for. *pixel : float The scalar pixel coordinates at which to evaluate the derivatives. normalize_by_world : bool If `True`, the matrix is normalized so that for each world entry the derivatives add up to 1. """ # Find the world coordinates at the requested pixel pixel_ref = np.array(pixel) world_ref = np.array(wcs.pixel_to_world_values(*pixel_ref)) # Set up the derivative matrix derivatives = np.zeros((wcs.world_n_dim, wcs.pixel_n_dim)) for i in range(wcs.pixel_n_dim): pixel_off = pixel_ref.copy() pixel_off[i] += 1 world_off = np.array(wcs.pixel_to_world_values(*pixel_off)) derivatives[:, i] = world_off - world_ref if normalize_by_world: derivatives /= derivatives.sum(axis=0)[:, np.newaxis] return derivatives
Objective function for fitting linear terms. Parameters ---------- params : array 6 element array. First 4 elements are PC matrix, last 2 are CRPIX. lon, lat: array Sky coordinates. x, y: array Pixel coordinates w_obj: `~astropy.wcs.WCS` WCS object
def _linear_wcs_fit(params, lon, lat, x, y, w_obj): """ Objective function for fitting linear terms. Parameters ---------- params : array 6 element array. First 4 elements are PC matrix, last 2 are CRPIX. lon, lat: array Sky coordinates. x, y: array Pixel coordinates w_obj: `~astropy.wcs.WCS` WCS object """ cd = params[0:4] crpix = params[4:6] w_obj.wcs.cd = ((cd[0], cd[1]), (cd[2], cd[3])) w_obj.wcs.crpix = crpix lon2, lat2 = w_obj.wcs_pix2world(x, y, 0) lat_resids = lat - lat2 lon_resids = lon - lon2 # In case the longitude has wrapped around lon_resids = np.mod(lon_resids - 180.0, 360.0) - 180.0 resids = np.concatenate((lon_resids * np.cos(np.radians(lat)), lat_resids)) return resids
Objective function for fitting SIP. Parameters ---------- params : array Fittable parameters. First 4 elements are PC matrix, last 2 are CRPIX. lon, lat: array Sky coordinates. u, v: array Pixel coordinates w_obj: `~astropy.wcs.WCS` WCS object
def _sip_fit(params, lon, lat, u, v, w_obj, order, coeff_names): """Objective function for fitting SIP. Parameters ---------- params : array Fittable parameters. First 4 elements are PC matrix, last 2 are CRPIX. lon, lat: array Sky coordinates. u, v: array Pixel coordinates w_obj: `~astropy.wcs.WCS` WCS object """ from astropy.modeling.models import SIP # here to avoid circular import # unpack params crpix = params[0:2] cdx = params[2:6].reshape((2, 2)) a_params = params[6 : 6 + len(coeff_names)] b_params = params[6 + len(coeff_names) :] # assign to wcs, used for transformations in this function w_obj.wcs.cd = cdx w_obj.wcs.crpix = crpix a_coeff, b_coeff = {}, {} for i in range(len(coeff_names)): a_coeff["A_" + coeff_names[i]] = a_params[i] b_coeff["B_" + coeff_names[i]] = b_params[i] sip = SIP( crpix=crpix, a_order=order, b_order=order, a_coeff=a_coeff, b_coeff=b_coeff ) fuv, guv = sip(u, v) xo, yo = np.dot(cdx, np.array([u + fuv - crpix[0], v + guv - crpix[1]])) # use all pix2world in case `projection` contains distortion table x, y = w_obj.all_world2pix(lon, lat, 0) x, y = np.dot(w_obj.wcs.cd, (x - w_obj.wcs.crpix[0], y - w_obj.wcs.crpix[1])) resids = np.concatenate((x - xo, y - yo)) return resids
Given two matching sets of coordinates on detector and sky, compute the WCS. Fits a WCS object to matched set of input detector and sky coordinates. Optionally, a SIP can be fit to account for geometric distortion. Returns an `~astropy.wcs.WCS` object with the best fit parameters for mapping between input pixel and sky coordinates. The projection type (default 'TAN') can passed in as a string, one of the valid three-letter projection codes - or as a WCS object with projection keywords already set. Note that if an input WCS has any non-polynomial distortion, this will be applied and reflected in the fit terms and coefficients. Passing in a WCS object in this way essentially allows it to be refit based on the matched input coordinates and projection point, but take care when using this option as non-projection related keywords in the input might cause unexpected behavior. Notes ----- - The fiducial point for the spherical projection can be set to 'center' to use the mean position of input sky coordinates, or as an `~astropy.coordinates.SkyCoord` object. - Units in all output WCS objects will always be in degrees. - If the coordinate frame differs between `~astropy.coordinates.SkyCoord` objects passed in for ``world_coords`` and ``proj_point``, the frame for ``world_coords`` will override as the frame for the output WCS. - If a WCS object is passed in to ``projection`` the CD/PC matrix will be used as an initial guess for the fit. If this is known to be significantly off and may throw off the fit, set to the identity matrix (for example, by doing wcs.wcs.pc = [(1., 0.,), (0., 1.)]) Parameters ---------- xy : (`numpy.ndarray`, `numpy.ndarray`) tuple x & y pixel coordinates. These should be in FITS convention, starting from (1,1) as the center of the bottom-left pixel. world_coords : `~astropy.coordinates.SkyCoord` Skycoord object with world coordinates. proj_point : 'center' or ~astropy.coordinates.SkyCoord` Defaults to 'center', in which the geometric center of input world coordinates will be used as the projection point. To specify an exact point for the projection, a Skycoord object with a coordinate pair can be passed in. For consistency, the units and frame of these coordinates will be transformed to match ``world_coords`` if they don't. projection : str or `~astropy.wcs.WCS` Three letter projection code, of any of standard projections defined in the FITS WCS standard. Optionally, a WCS object with projection keywords set may be passed in. sip_degree : None or int If set to a non-zero integer value, will fit SIP of degree ``sip_degree`` to model geometric distortion. Defaults to None, meaning no distortion corrections will be fit. Returns ------- wcs : `~astropy.wcs.WCS` The best-fit WCS to the points given.
def fit_wcs_from_points( xy, world_coords, proj_point="center", projection="TAN", sip_degree=None ): """ Given two matching sets of coordinates on detector and sky, compute the WCS. Fits a WCS object to matched set of input detector and sky coordinates. Optionally, a SIP can be fit to account for geometric distortion. Returns an `~astropy.wcs.WCS` object with the best fit parameters for mapping between input pixel and sky coordinates. The projection type (default 'TAN') can passed in as a string, one of the valid three-letter projection codes - or as a WCS object with projection keywords already set. Note that if an input WCS has any non-polynomial distortion, this will be applied and reflected in the fit terms and coefficients. Passing in a WCS object in this way essentially allows it to be refit based on the matched input coordinates and projection point, but take care when using this option as non-projection related keywords in the input might cause unexpected behavior. Notes ----- - The fiducial point for the spherical projection can be set to 'center' to use the mean position of input sky coordinates, or as an `~astropy.coordinates.SkyCoord` object. - Units in all output WCS objects will always be in degrees. - If the coordinate frame differs between `~astropy.coordinates.SkyCoord` objects passed in for ``world_coords`` and ``proj_point``, the frame for ``world_coords`` will override as the frame for the output WCS. - If a WCS object is passed in to ``projection`` the CD/PC matrix will be used as an initial guess for the fit. If this is known to be significantly off and may throw off the fit, set to the identity matrix (for example, by doing wcs.wcs.pc = [(1., 0.,), (0., 1.)]) Parameters ---------- xy : (`numpy.ndarray`, `numpy.ndarray`) tuple x & y pixel coordinates. These should be in FITS convention, starting from (1,1) as the center of the bottom-left pixel. world_coords : `~astropy.coordinates.SkyCoord` Skycoord object with world coordinates. proj_point : 'center' or ~astropy.coordinates.SkyCoord` Defaults to 'center', in which the geometric center of input world coordinates will be used as the projection point. To specify an exact point for the projection, a Skycoord object with a coordinate pair can be passed in. For consistency, the units and frame of these coordinates will be transformed to match ``world_coords`` if they don't. projection : str or `~astropy.wcs.WCS` Three letter projection code, of any of standard projections defined in the FITS WCS standard. Optionally, a WCS object with projection keywords set may be passed in. sip_degree : None or int If set to a non-zero integer value, will fit SIP of degree ``sip_degree`` to model geometric distortion. Defaults to None, meaning no distortion corrections will be fit. Returns ------- wcs : `~astropy.wcs.WCS` The best-fit WCS to the points given. """ from scipy.optimize import least_squares import astropy.units as u from astropy.coordinates import SkyCoord # here to avoid circular import from .wcs import Sip xp, yp = xy try: lon, lat = world_coords.data.lon.deg, world_coords.data.lat.deg except AttributeError: unit_sph = world_coords.unit_spherical lon, lat = unit_sph.lon.deg, unit_sph.lat.deg # verify input if (type(proj_point) != type(world_coords)) and (proj_point != "center"): raise ValueError( "proj_point must be set to 'center', or an" "`~astropy.coordinates.SkyCoord` object with " "a pair of points." ) use_center_as_proj_point = str(proj_point) == "center" if not use_center_as_proj_point: assert proj_point.size == 1 proj_codes = [ "AZP", "SZP", "TAN", "STG", "SIN", "ARC", "ZEA", "AIR", "CYP", "CEA", "CAR", "MER", "SFL", "PAR", "MOL", "AIT", "COP", "COE", "COD", "COO", "BON", "PCO", "TSC", "CSC", "QSC", "HPX", "XPH", ] if type(projection) == str: if projection not in proj_codes: raise ValueError( "Must specify valid projection code from list of supported types: ", ", ".join(proj_codes), ) # empty wcs to fill in with fit values wcs = celestial_frame_to_wcs(frame=world_coords.frame, projection=projection) else: # if projection is not string, should be wcs object. use as template. wcs = copy.deepcopy(projection) wcs.wcs.cdelt = (1.0, 1.0) # make sure cdelt is 1 wcs.sip = None # Change PC to CD, since cdelt will be set to 1 if wcs.wcs.has_pc(): wcs.wcs.cd = wcs.wcs.pc wcs.wcs.__delattr__("pc") if (type(sip_degree) != type(None)) and (type(sip_degree) != int): raise ValueError("sip_degree must be None, or integer.") # compute bounding box for sources in image coordinates: xpmin, xpmax, ypmin, ypmax = xp.min(), xp.max(), yp.min(), yp.max() # set pixel_shape to span of input points wcs.pixel_shape = ( 1 if xpmax <= 0.0 else int(np.ceil(xpmax)), 1 if ypmax <= 0.0 else int(np.ceil(ypmax)), ) # determine CRVAL from input close = lambda l, p: p[np.argmin(np.abs(l))] if use_center_as_proj_point: # use center of input points sc1 = SkyCoord(lon.min() * u.deg, lat.max() * u.deg) sc2 = SkyCoord(lon.max() * u.deg, lat.min() * u.deg) pa = sc1.position_angle(sc2) sep = sc1.separation(sc2) midpoint_sc = sc1.directional_offset_by(pa, sep / 2) wcs.wcs.crval = (midpoint_sc.data.lon.deg, midpoint_sc.data.lat.deg) wcs.wcs.crpix = ((xpmax + xpmin) / 2.0, (ypmax + ypmin) / 2.0) else: # convert units, initial guess for crpix proj_point.transform_to(world_coords) wcs.wcs.crval = (proj_point.data.lon.deg, proj_point.data.lat.deg) wcs.wcs.crpix = ( close(lon - wcs.wcs.crval[0], xp + 1), close(lon - wcs.wcs.crval[1], yp + 1), ) # fit linear terms, assign to wcs # use (1, 0, 0, 1) as initial guess, in case input wcs was passed in # and cd terms are way off. # Use bounds to require that the fit center pixel is on the input image if xpmin == xpmax: xpmin, xpmax = xpmin - 0.5, xpmax + 0.5 if ypmin == ypmax: ypmin, ypmax = ypmin - 0.5, ypmax + 0.5 p0 = np.concatenate([wcs.wcs.cd.flatten(), wcs.wcs.crpix.flatten()]) fit = least_squares( _linear_wcs_fit, p0, args=(lon, lat, xp, yp, wcs), bounds=[ [-np.inf, -np.inf, -np.inf, -np.inf, xpmin + 1, ypmin + 1], [np.inf, np.inf, np.inf, np.inf, xpmax + 1, ypmax + 1], ], ) wcs.wcs.crpix = np.array(fit.x[4:6]) wcs.wcs.cd = np.array(fit.x[0:4].reshape((2, 2))) # fit SIP, if specified. Only fit forward coefficients if sip_degree: degree = sip_degree if "-SIP" not in wcs.wcs.ctype[0]: wcs.wcs.ctype = [x + "-SIP" for x in wcs.wcs.ctype] coef_names = [ f"{i}_{j}" for i in range(degree + 1) for j in range(degree + 1) if (i + j) < (degree + 1) and (i + j) > 1 ] p0 = np.concatenate( ( np.array(wcs.wcs.crpix), wcs.wcs.cd.flatten(), np.zeros(2 * len(coef_names)), ) ) fit = least_squares( _sip_fit, p0, args=(lon, lat, xp, yp, wcs, degree, coef_names), bounds=[ [xpmin + 1, ypmin + 1] + [-np.inf] * (4 + 2 * len(coef_names)), [xpmax + 1, ypmax + 1] + [np.inf] * (4 + 2 * len(coef_names)), ], ) coef_fit = ( list(fit.x[6 : 6 + len(coef_names)]), list(fit.x[6 + len(coef_names) :]), ) # put fit values in wcs wcs.wcs.cd = fit.x[2:6].reshape((2, 2)) wcs.wcs.crpix = fit.x[0:2] a_vals = np.zeros((degree + 1, degree + 1)) b_vals = np.zeros((degree + 1, degree + 1)) for coef_name in coef_names: a_vals[int(coef_name[0])][int(coef_name[2])] = coef_fit[0].pop(0) b_vals[int(coef_name[0])][int(coef_name[2])] = coef_fit[1].pop(0) wcs.sip = Sip( a_vals, b_vals, np.zeros((degree + 1, degree + 1)), np.zeros((degree + 1, degree + 1)), wcs.wcs.crpix, ) return wcs
Convert a WCS obsgeo property into an ITRS coordinate frame. Parameters ---------- obsgeo : array-like A shape ``(6, )`` array representing ``OBSGEO-[XYZ], OBSGEO-[BLH]`` as returned by ``WCS.wcs.obsgeo``. obstime : time-like The time associated with the coordinate, will be passed to `~astropy.coordinates.ITRS` as the obstime keyword. Returns ------- ~astropy.coordinates.ITRS An `~astropy.coordinates.ITRS` coordinate frame representing the coordinates. Notes ----- The obsgeo array as accessed on a `.WCS` object is a length 6 numpy array where the first three elements are the coordinate in a cartesian representation and the second 3 are the coordinate in a spherical representation. This function priorities reading the cartesian coordinates, and will only read the spherical coordinates if the cartesian coordinates are either all zero or any of the cartesian coordinates are non-finite. In the case where both the spherical and cartesian coordinates have some non-finite values the spherical coordinates will be returned with the non-finite values included.
def obsgeo_to_frame(obsgeo, obstime): """ Convert a WCS obsgeo property into an ITRS coordinate frame. Parameters ---------- obsgeo : array-like A shape ``(6, )`` array representing ``OBSGEO-[XYZ], OBSGEO-[BLH]`` as returned by ``WCS.wcs.obsgeo``. obstime : time-like The time associated with the coordinate, will be passed to `~astropy.coordinates.ITRS` as the obstime keyword. Returns ------- ~astropy.coordinates.ITRS An `~astropy.coordinates.ITRS` coordinate frame representing the coordinates. Notes ----- The obsgeo array as accessed on a `.WCS` object is a length 6 numpy array where the first three elements are the coordinate in a cartesian representation and the second 3 are the coordinate in a spherical representation. This function priorities reading the cartesian coordinates, and will only read the spherical coordinates if the cartesian coordinates are either all zero or any of the cartesian coordinates are non-finite. In the case where both the spherical and cartesian coordinates have some non-finite values the spherical coordinates will be returned with the non-finite values included. """ if ( obsgeo is None or len(obsgeo) != 6 or np.all(np.array(obsgeo) == 0) or np.all(~np.isfinite(obsgeo)) ): raise ValueError( f"Can not parse the 'obsgeo' location ({obsgeo}). " "obsgeo should be a length 6 non-zero, finite numpy array" ) # If the cartesian coords are zero or have NaNs in them use the spherical ones if np.all(obsgeo[:3] == 0) or np.any(~np.isfinite(obsgeo[:3])): data = SphericalRepresentation(*(obsgeo[3:] * (u.deg, u.deg, u.m))) # Otherwise we assume the cartesian ones are valid else: data = CartesianRepresentation(*obsgeo[:3] * u.m) return ITRS(data, obstime=obstime)
Unpickles a WCS object from a serialized FITS string.
def __WCS_unpickle__(cls, dct, fits_data): """ Unpickles a WCS object from a serialized FITS string. """ self = cls.__new__(cls) buffer = io.BytesIO(fits_data) hdulist = fits.open(buffer) naxis = dct.pop("naxis", None) if naxis: hdulist[0].header["naxis"] = naxis naxes = dct.pop("_naxis", []) for k, na in enumerate(naxes): hdulist[0].header[f"naxis{k + 1:d}"] = na kwargs = dct.pop("_init_kwargs", {}) self.__dict__.update(dct) wcskey = dct.pop("_alt_wcskey", " ") WCS.__init__(self, hdulist[0].header, hdulist, key=wcskey, **kwargs) self.pixel_bounds = dct.get("_pixel_bounds", None) return self
Find all the WCS transformations in the given header. Parameters ---------- header : str or `~astropy.io.fits.Header` object. relax : bool or int, optional Degree of permissiveness: - `True` (default): Admit all recognized informal extensions of the WCS standard. - `False`: Recognize only FITS keywords defined by the published WCS standard. - `int`: a bit field selecting specific extensions to accept. See :ref:`astropy:relaxread` for details. keysel : sequence of str, optional A list of flags used to select the keyword types considered by wcslib. When ``None``, only the standard image header keywords are considered (and the underlying wcspih() C function is called). To use binary table image array or pixel list keywords, *keysel* must be set. Each element in the list should be one of the following strings: - 'image': Image header keywords - 'binary': Binary table image array keywords - 'pixel': Pixel list keywords Keywords such as ``EQUIna`` or ``RFRQna`` that are common to binary table image arrays and pixel lists (including ``WCSNna`` and ``TWCSna``) are selected by both 'binary' and 'pixel'. fix : bool, optional When `True` (default), call `~astropy.wcs.Wcsprm.fix` on the resulting objects to fix any non-standard uses in the header. `FITSFixedWarning` warnings will be emitted if any changes were made. translate_units : str, optional Specify which potentially unsafe translations of non-standard unit strings to perform. By default, performs none. See `WCS.fix` for more information about this parameter. Only effective when ``fix`` is `True`. Returns ------- wcses : list of `WCS`
def find_all_wcs( header, relax=True, keysel=None, fix=True, translate_units="", _do_set=True ): """ Find all the WCS transformations in the given header. Parameters ---------- header : str or `~astropy.io.fits.Header` object. relax : bool or int, optional Degree of permissiveness: - `True` (default): Admit all recognized informal extensions of the WCS standard. - `False`: Recognize only FITS keywords defined by the published WCS standard. - `int`: a bit field selecting specific extensions to accept. See :ref:`astropy:relaxread` for details. keysel : sequence of str, optional A list of flags used to select the keyword types considered by wcslib. When ``None``, only the standard image header keywords are considered (and the underlying wcspih() C function is called). To use binary table image array or pixel list keywords, *keysel* must be set. Each element in the list should be one of the following strings: - 'image': Image header keywords - 'binary': Binary table image array keywords - 'pixel': Pixel list keywords Keywords such as ``EQUIna`` or ``RFRQna`` that are common to binary table image arrays and pixel lists (including ``WCSNna`` and ``TWCSna``) are selected by both 'binary' and 'pixel'. fix : bool, optional When `True` (default), call `~astropy.wcs.Wcsprm.fix` on the resulting objects to fix any non-standard uses in the header. `FITSFixedWarning` warnings will be emitted if any changes were made. translate_units : str, optional Specify which potentially unsafe translations of non-standard unit strings to perform. By default, performs none. See `WCS.fix` for more information about this parameter. Only effective when ``fix`` is `True`. Returns ------- wcses : list of `WCS` """ if isinstance(header, (str, bytes)): header_string = header elif isinstance(header, fits.Header): header_string = header.tostring() else: raise TypeError("header must be a string or astropy.io.fits.Header object") keysel_flags = _parse_keysel(keysel) if isinstance(header_string, str): header_bytes = header_string.encode("ascii") else: header_bytes = header_string wcsprms = _wcs.find_all_wcs(header_bytes, relax, keysel_flags) result = [] for wcsprm in wcsprms: subresult = WCS(fix=False, _do_set=False) subresult.wcs = wcsprm result.append(subresult) if fix: subresult.fix(translate_units) if _do_set: subresult.wcs.set() return result
Prints a WCS validation report for the given FITS file. Parameters ---------- source : str or file-like or `~astropy.io.fits.HDUList` The FITS file to validate. Returns ------- results : list subclass instance The result is returned as nested lists. The first level corresponds to the HDUs in the given file. The next level has an entry for each WCS found in that header. The special subclass of list will pretty-print the results as a table when printed.
def validate(source): """ Prints a WCS validation report for the given FITS file. Parameters ---------- source : str or file-like or `~astropy.io.fits.HDUList` The FITS file to validate. Returns ------- results : list subclass instance The result is returned as nested lists. The first level corresponds to the HDUs in the given file. The next level has an entry for each WCS found in that header. The special subclass of list will pretty-print the results as a table when printed. """ class _WcsValidateWcsResult(list): def __init__(self, key): self._key = key def __repr__(self): result = [f" WCS key '{self._key or ' '}':"] if len(self): for entry in self: for i, line in enumerate(entry.splitlines()): if i == 0: initial_indent = " - " else: initial_indent = " " result.extend( textwrap.wrap( line, initial_indent=initial_indent, subsequent_indent=" ", ) ) else: result.append(" No issues.") return "\n".join(result) class _WcsValidateHduResult(list): def __init__(self, hdu_index, hdu_name): self._hdu_index = hdu_index self._hdu_name = hdu_name list.__init__(self) def __repr__(self): if len(self): if self._hdu_name: hdu_name = f" ({self._hdu_name})" else: hdu_name = "" result = [f"HDU {self._hdu_index}{hdu_name}:"] for wcs in self: result.append(repr(wcs)) return "\n".join(result) return "" class _WcsValidateResults(list): def __repr__(self): result = [] for hdu in self: content = repr(hdu) if len(content): result.append(content) return "\n\n".join(result) global __warningregistry__ if isinstance(source, fits.HDUList): hdulist = source close_file = False else: hdulist = fits.open(source) close_file = True results = _WcsValidateResults() for i, hdu in enumerate(hdulist): hdu_results = _WcsValidateHduResult(i, hdu.name) results.append(hdu_results) with warnings.catch_warnings(record=True) as warning_lines: wcses = find_all_wcs( hdu.header, relax=_wcs.WCSHDR_reject, fix=False, _do_set=False ) for wcs in wcses: wcs_results = _WcsValidateWcsResult(wcs.wcs.alt) hdu_results.append(wcs_results) try: del __warningregistry__ except NameError: pass with warnings.catch_warnings(record=True) as warning_lines: warnings.resetwarnings() warnings.simplefilter("always", FITSFixedWarning, append=True) try: WCS( hdu.header, hdulist, key=wcs.wcs.alt or " ", relax=_wcs.WCSHDR_reject, fix=True, _do_set=False, ) except WcsError as e: wcs_results.append(str(e)) wcs_results.extend([str(x.message) for x in warning_lines]) if close_file: hdulist.close() return results
Get the path to astropy.wcs's C header files.
def get_include(): """ Get the path to astropy.wcs's C header files. """ import os return os.path.join(os.path.dirname(__file__), "include")
Test selection of a specific pixel list WCS using ``colsel``. See #11412.
def test_pixlist_wcs_colsel(): """ Test selection of a specific pixel list WCS using ``colsel``. See #11412. """ hdr_file = get_pkg_data_filename("data/chandra-pixlist-wcs.hdr") hdr = fits.Header.fromtextfile(hdr_file) with pytest.warns(wcs.FITSFixedWarning): w0 = wcs.WCS(hdr, keysel=["image", "pixel"], colsel=[11, 12]) with pytest.warns(wcs.FITSFixedWarning): w = pickle.loads(pickle.dumps(w0)) assert w.naxis == 2 assert list(w.wcs.ctype) == ["RA---TAN", "DEC--TAN"] assert np.allclose(w.wcs.crval, [229.38051931869, -58.81108068885]) assert np.allclose(w.wcs.pc, [[1, 0], [0, 1]]) assert np.allclose(w.wcs.cdelt, [-0.00013666666666666, 0.00013666666666666]) assert np.allclose(w.wcs.lonpole, 180.0)
This WCS has an almost linear correlation between the pixel and world axes close to the reference pixel.
def spatial_wcs_2d_small_angle(): """ This WCS has an almost linear correlation between the pixel and world axes close to the reference pixel. """ wcs = WCS(naxis=2) wcs.wcs.ctype = ["HPLN-TAN", "HPLT-TAN"] wcs.wcs.crpix = [3.0] * 2 wcs.wcs.cdelt = [0.002] * 2 wcs.wcs.crval = [0] * 2 wcs.wcs.set() return wcs
Regression test for https://github.com/astropy/astropy/pull/9609
def test_pixel_to_world_itrs(x_in, y_in): """Regression test for https://github.com/astropy/astropy/pull/9609""" if Version(_wcs.__version__) >= Version("7.4"): ctx = pytest.warns( FITSFixedWarning, match=( r"'datfix' made the change 'Set MJD-OBS to 57982\.528524 from" r" DATE-OBS'\." ), ) else: ctx = nullcontext() with ctx: wcs = WCS( { "NAXIS": 2, "CTYPE1": "TLON-CAR", "CTYPE2": "TLAT-CAR", "RADESYS": "ITRS ", "DATE-OBS": "2017-08-17T12:41:04.444", } ) # This shouldn't raise an exception. coord = wcs.pixel_to_world(x_in, y_in) # Check round trip transformation. x, y = wcs.world_to_pixel(coord) np.testing.assert_almost_equal(x, x_in) np.testing.assert_almost_equal(y, y_in)
From github issue #36
def test_fixes(): """ From github issue #36 """ header = get_pkg_data_contents("data/nonstandard_units.hdr", encoding="binary") with ( pytest.raises(wcs.InvalidTransformError), pytest.warns(wcs.FITSFixedWarning) as w, ): wcs.WCS(header, translate_units="dhs") if Version("7.4") <= _WCSLIB_VER < Version("7.6"): assert len(w) == 3 assert "'datfix' made the change 'Success'." in str(w.pop().message) else: assert len(w) == 2 first_wmsg = str(w[0].message) assert "unitfix" in first_wmsg and "Hz" in first_wmsg and "M/S" in first_wmsg assert "plane angle" in str(w[1].message) and "m/s" in str(w[1].message)
From github issue #107
def test_outside_sky(): """ From github issue #107 """ header = get_pkg_data_contents("data/outside_sky.hdr", encoding="binary") w = wcs.WCS(header) assert np.all(np.isnan(w.wcs_pix2world([[100.0, 500.0]], 0))) # outside sky assert np.all(np.isnan(w.wcs_pix2world([[200.0, 200.0]], 0))) # outside sky assert not np.any(np.isnan(w.wcs_pix2world([[1000.0, 1000.0]], 0)))
From github issue #1463
def test_pix2world(): """ From github issue #1463 """ # TODO: write this to test the expected output behavior of pix2world, # currently this just makes sure it doesn't error out in unexpected ways # (and compares `wcs.pc` and `result` values?) filename = get_pkg_data_filename("data/sip2.fits") with pytest.warns(wcs.FITSFixedWarning) as caught_warnings: # this raises a warning unimportant for this testing the pix2world # FITSFixedWarning(u'The WCS transformation has more axes (2) than # the image it is associated with (0)') ww = wcs.WCS(filename) # might as well monitor for changing behavior if Version("7.4") <= _WCSLIB_VER < Version("7.6"): assert len(caught_warnings) == 2 else: assert len(caught_warnings) == 1 n = 3 pixels = (np.arange(n) * np.ones((2, n))).T result = ww.wcs_pix2world(pixels, 0, ra_dec_order=True) # Catch #2791 ww.wcs_pix2world(pixels[..., 0], pixels[..., 1], 0, ra_dec_order=True) # assuming that the data of sip2.fits doesn't change answer = np.array([[0.00024976, 0.00023018], [0.00023043, -0.00024997]]) assert np.allclose(ww.wcs.pc, answer, atol=1.0e-8) answer = np.array( [ [202.39265216, 47.17756518], [202.39335826, 47.17754619], [202.39406436, 47.1775272], ] ) assert np.allclose(result, answer, atol=1.0e-8, rtol=1.0e-10)
Test that WCS can be initialized with a dict-like object
def test_dict_init(): """ Test that WCS can be initialized with a dict-like object """ # Dictionary with no actual WCS, returns identity transform with ctx_for_v71_dateref_warnings(): w = wcs.WCS({}) xp, yp = w.wcs_world2pix(41.0, 2.0, 1) assert_array_almost_equal_nulp(xp, 41.0, 10) assert_array_almost_equal_nulp(yp, 2.0, 10) # Valid WCS hdr = { "CTYPE1": "GLON-CAR", "CTYPE2": "GLAT-CAR", "CUNIT1": "deg", "CUNIT2": "deg", "CRPIX1": 1, "CRPIX2": 1, "CRVAL1": 40.0, "CRVAL2": 0.0, "CDELT1": -0.1, "CDELT2": 0.1, } if _WCSLIB_VER >= Version("7.1"): hdr["DATEREF"] = "1858-11-17" if _WCSLIB_VER >= Version("7.4"): ctx = pytest.warns( wcs.wcs.FITSFixedWarning, match=r"'datfix' made the change 'Set MJDREF to 0\.000000 from DATEREF'\.", ) else: ctx = nullcontext() with ctx: w = wcs.WCS(hdr) xp, yp = w.wcs_world2pix(41.0, 2.0, 0) assert_array_almost_equal_nulp(xp, -10.0, 10) assert_array_almost_equal_nulp(yp, 20.0, 10)
Issue #444
def test_extra_kwarg(): """ Issue #444 """ w = wcs.WCS() with NumpyRNGContext(123456789): data = np.random.rand(100, 2) with pytest.raises(TypeError): w.wcs_pix2world(data, origin=1)
Issue #444
def test_3d_shapes(): """ Issue #444 """ w = wcs.WCS(naxis=3) with NumpyRNGContext(123456789): data = np.random.rand(100, 3) result = w.wcs_pix2world(data, 1) assert result.shape == (100, 3) result = w.wcs_pix2world(data[..., 0], data[..., 1], data[..., 2], 1) assert len(result) == 3
Issue #1395
def test_invalid_shape(): """Issue #1395""" MESSAGE = r"When providing two arguments, the array must be of shape [(]N, 2[)]" w = wcs.WCS(naxis=2) xy = np.random.random((2, 3)) with pytest.raises(ValueError, match=MESSAGE): w.wcs_pix2world(xy, 1) xy = np.random.random((2, 1)) with pytest.raises(ValueError, match=MESSAGE): w.wcs_pix2world(xy, 1)
Causes a double free without a recent fix in wcslib_wrap.C
def test_find_all_wcs_crash(): """ Causes a double free without a recent fix in wcslib_wrap.C """ with open(get_pkg_data_filename("data/too_many_pv.hdr")) as fd: header = fd.read() # We have to set fix=False here, because one of the fixing tasks is to # remove redundant SCAMP distortion parameters when SIP distortion # parameters are also present. with pytest.raises(wcs.InvalidTransformError), pytest.warns(wcs.FITSFixedWarning): wcs.find_all_wcs(header, fix=False)
Test all_world2pix, iterative inverse of all_pix2world
def test_all_world2pix( fname=None, ext=0, tolerance=1.0e-4, origin=0, random_npts=25000, adaptive=False, maxiter=20, detect_divergence=True, ): """Test all_world2pix, iterative inverse of all_pix2world""" # Open test FITS file: if fname is None: fname = get_pkg_data_filename("data/j94f05bgq_flt.fits") ext = ("SCI", 1) if not os.path.isfile(fname): raise OSError(f"Input file '{fname:s}' to 'test_all_world2pix' not found.") h = fits.open(fname) w = wcs.WCS(h[ext].header, h) h.close() del h crpix = w.wcs.crpix ncoord = crpix.shape[0] # Assume that CRPIX is at the center of the image and that the image has # a power-of-2 number of pixels along each axis. Only use the central # 1/64 for this testing purpose: naxesi_l = list((7.0 / 16 * crpix).astype(int)) naxesi_u = list((9.0 / 16 * crpix).astype(int)) # Generate integer indices of pixels (image grid): img_pix = np.dstack( [i.flatten() for i in np.meshgrid(*map(range, naxesi_l, naxesi_u))] )[0] # Generate random data (in image coordinates): with NumpyRNGContext(123456789): rnd_pix = np.random.rand(random_npts, ncoord) # Scale random data to cover the central part of the image mwidth = 2 * (crpix * 1.0 / 8) rnd_pix = crpix - 0.5 * mwidth + (mwidth - 1) * rnd_pix # Reference pixel coordinates in image coordinate system (CS): test_pix = np.append(img_pix, rnd_pix, axis=0) # Reference pixel coordinates in sky CS using forward transformation: all_world = w.all_pix2world(test_pix, origin) try: runtime_begin = datetime.now() # Apply the inverse iterative process to pixels in world coordinates # to recover the pixel coordinates in image space. all_pix = w.all_world2pix( all_world, origin, tolerance=tolerance, adaptive=adaptive, maxiter=maxiter, detect_divergence=detect_divergence, ) runtime_end = datetime.now() except wcs.wcs.NoConvergence as e: runtime_end = datetime.now() ndiv = 0 if e.divergent is not None: ndiv = e.divergent.shape[0] print(f"There are {ndiv} diverging solutions.") print(f"Indices of diverging solutions:\n{e.divergent}") print(f"Diverging solutions:\n{e.best_solution[e.divergent]}\n") print( "Mean radius of the diverging solutions:" f" {np.mean(np.linalg.norm(e.best_solution[e.divergent], axis=1))}" ) print( "Mean accuracy of the diverging solutions:" f" {np.mean(np.linalg.norm(e.accuracy[e.divergent], axis=1))}\n" ) else: print("There are no diverging solutions.") nslow = 0 if e.slow_conv is not None: nslow = e.slow_conv.shape[0] print(f"There are {nslow} slowly converging solutions.") print(f"Indices of slowly converging solutions:\n{e.slow_conv}") print(f"Slowly converging solutions:\n{e.best_solution[e.slow_conv]}\n") else: print("There are no slowly converging solutions.\n") print( f"There are {e.best_solution.shape[0] - ndiv - nslow} converged solutions." ) print(f"Best solutions (all points):\n{e.best_solution}") print(f"Accuracy:\n{e.accuracy}\n") print( "\nFinished running 'test_all_world2pix' with errors.\n" f"ERROR: {e.args[0]}\nRun time: {runtime_end - runtime_begin}\n" ) raise e # Compute differences between reference pixel coordinates and # pixel coordinates (in image space) recovered from reference # pixels in world coordinates: errors = np.sqrt(np.sum(np.power(all_pix - test_pix, 2), axis=1)) meanerr = np.mean(errors) maxerr = np.amax(errors) print( "\nFinished running 'test_all_world2pix'.\n" f"Mean error = {meanerr:e} (Max error = {maxerr:e})\n" f"Run time: {runtime_end - runtime_begin}\n" ) assert maxerr < 2.0 * tolerance
Test parsing of WCS parameters with redundant SIP and SCAMP distortion parameters.
def test_scamp_sip_distortion_parameters(): """ Test parsing of WCS parameters with redundant SIP and SCAMP distortion parameters. """ header = get_pkg_data_contents("data/validate.fits", encoding="binary") with pytest.warns(wcs.FITSFixedWarning): w = wcs.WCS(header) # Just check that this doesn't raise an exception. w.all_pix2world(0, 0, 0)
From github issue #1854
def test_fixes2(): """ From github issue #1854 """ header = get_pkg_data_contents("data/nonstandard_units.hdr", encoding="binary") with pytest.raises(wcs.InvalidTransformError): wcs.WCS(header, fix=False)
From github issue #1918
def test_unit_normalization(): """ From github issue #1918 """ header = get_pkg_data_contents("data/unit.hdr", encoding="binary") w = wcs.WCS(header) assert w.wcs.cunit[2] == "m/s"
From github issue #1912
def test_footprint_to_file(tmp_path): """ From github issue #1912 """ # Arbitrary keywords from real data hdr = { "CTYPE1": "RA---ZPN", "CRUNIT1": "deg", "CRPIX1": -3.3495999e02, "CRVAL1": 3.185790700000e02, "CTYPE2": "DEC--ZPN", "CRUNIT2": "deg", "CRPIX2": 3.0453999e03, "CRVAL2": 4.388538000000e01, "PV2_1": 1.0, "PV2_3": 220.0, "NAXIS1": 2048, "NAXIS2": 1024, } w = wcs.WCS(hdr) testfile = tmp_path / "test.txt" w.footprint_to_file(testfile) with open(testfile) as f: lines = f.readlines() assert len(lines) == 4 assert lines[2] == "ICRS\n" assert "color=green" in lines[3] w.footprint_to_file(testfile, coordsys="FK5", color="red") with open(testfile) as f: lines = f.readlines() assert len(lines) == 4 assert lines[2] == "FK5\n" assert "color=red" in lines[3] with pytest.raises(ValueError): w.footprint_to_file(testfile, coordsys="FOO") del hdr["NAXIS1"] del hdr["NAXIS2"] w = wcs.WCS(hdr) with pytest.warns(AstropyUserWarning): w.footprint_to_file(testfile)
From github issue #2053
def test_validate_faulty_wcs(): """ From github issue #2053 """ h = fits.Header() # Illegal WCS: h["RADESYSA"] = "ICRS" h["PV2_1"] = 1.0 hdu = fits.PrimaryHDU([[0]], header=h) hdulist = fits.HDUList([hdu]) # Check that this doesn't raise a NameError exception wcs.validate(hdulist)
Test calc_footprint without distortion.
def test_calc_footprint_2(): """Test calc_footprint without distortion.""" fits = get_pkg_data_filename("data/sip.fits") with pytest.warns(wcs.FITSFixedWarning): w = wcs.WCS(fits) axes = (1000, 1051) ref = np.array( [ [202.39265216, 47.17756518], [202.7469062, 46.91483312], [203.11487481, 47.14359319], [202.76092671, 47.40745948], ] ) footprint = w.calc_footprint(axes=axes, undistort=False) assert_allclose(footprint, ref)
Test calc_footprint with corner of the pixel.
def test_calc_footprint_3(): """Test calc_footprint with corner of the pixel.""" w = wcs.WCS() w.wcs.ctype = ["GLON-CAR", "GLAT-CAR"] w.wcs.crpix = [1.5, 5.5] w.wcs.cdelt = [-0.1, 0.1] axes = (2, 10) ref = np.array([[0.1, -0.5], [0.1, 0.5], [359.9, 0.5], [359.9, -0.5]]) footprint = w.calc_footprint(axes=axes, undistort=False, center=False) assert_allclose(footprint, ref)
Just make sure that it runs
def test_printwcs(capsys): """ Just make sure that it runs """ h = get_pkg_data_contents("data/spectra/orion-freq-1.hdr", encoding="binary") with pytest.warns(wcs.FITSFixedWarning): w = wcs.WCS(h) w.printwcs() captured = capsys.readouterr() assert "WCS Keywords" in captured.out h = get_pkg_data_contents("data/3d_cd.hdr", encoding="binary") w = wcs.WCS(h) w.printwcs() captured = capsys.readouterr() assert "WCS Keywords" in captured.out
Regression test for #3066
def test_no_iteration(): """Regression test for #3066""" MESSAGE = "'{}' object is not iterable" w = wcs.WCS(naxis=2) with pytest.raises(TypeError, match=MESSAGE.format("WCS")): iter(w) class NewWCS(wcs.WCS): pass w = NewWCS(naxis=2) with pytest.raises(TypeError, match=MESSAGE.format("NewWCS")): iter(w)
Regression test for https://github.com/astropy/astropy/issues/4612
def test_no_truncate_crval(): """ Regression test for https://github.com/astropy/astropy/issues/4612 """ w = wcs.WCS(naxis=3) w.wcs.crval = [50, 50, 2.12345678e11] w.wcs.cdelt = [1e-3, 1e-3, 1e8] w.wcs.ctype = ["RA---TAN", "DEC--TAN", "FREQ"] w.wcs.set() header = w.to_header() for ii in range(3): assert header[f"CRVAL{ii + 1}"] == w.wcs.crval[ii] assert header[f"CDELT{ii + 1}"] == w.wcs.cdelt[ii]
Regression test for https://github.com/astropy/astropy/issues/4612
def test_no_truncate_crval_try2(): """ Regression test for https://github.com/astropy/astropy/issues/4612 """ w = wcs.WCS(naxis=3) w.wcs.crval = [50, 50, 2.12345678e11] w.wcs.cdelt = [1e-5, 1e-5, 1e5] w.wcs.ctype = ["RA---SIN", "DEC--SIN", "FREQ"] w.wcs.cunit = ["deg", "deg", "Hz"] w.wcs.crpix = [1, 1, 1] w.wcs.restfrq = 2.34e11 w.wcs.set() header = w.to_header() for ii in range(3): assert header[f"CRVAL{ii + 1}"] == w.wcs.crval[ii] assert header[f"CDELT{ii + 1}"] == w.wcs.cdelt[ii]
Regression test for https://github.com/astropy/astropy/issues/5162
def test_no_truncate_crval_p17(): """ Regression test for https://github.com/astropy/astropy/issues/5162 """ w = wcs.WCS(naxis=2) w.wcs.crval = [50.1234567890123456, 50.1234567890123456] w.wcs.cdelt = [1e-3, 1e-3] w.wcs.ctype = ["RA---TAN", "DEC--TAN"] w.wcs.set() header = w.to_header() assert header["CRVAL1"] != w.wcs.crval[0] assert header["CRVAL2"] != w.wcs.crval[1] header = w.to_header(relax=wcs.WCSHDO_P17) assert header["CRVAL1"] == w.wcs.crval[0] assert header["CRVAL2"] == w.wcs.crval[1]
Regression test for https://github.com/astropy/astropy/issues/4612 This one uses WCS.wcs.compare and some slightly different values
def test_no_truncate_using_compare(): """ Regression test for https://github.com/astropy/astropy/issues/4612 This one uses WCS.wcs.compare and some slightly different values """ w = wcs.WCS(naxis=3) w.wcs.crval = [2.409303333333e02, 50, 2.12345678e11] w.wcs.cdelt = [1e-3, 1e-3, 1e8] w.wcs.ctype = ["RA---TAN", "DEC--TAN", "FREQ"] w.wcs.set() w2 = wcs.WCS(w.to_header()) w.wcs.compare(w2.wcs)
Passing ImageHDU or PrimaryHDU and comparing it with wcs initialized from header. For #4493.
def test_passing_ImageHDU(): """ Passing ImageHDU or PrimaryHDU and comparing it with wcs initialized from header. For #4493. """ path = get_pkg_data_filename("data/validate.fits") with fits.open(path) as hdulist: with pytest.warns(wcs.FITSFixedWarning): wcs_hdu = wcs.WCS(hdulist[0]) wcs_header = wcs.WCS(hdulist[0].header) assert wcs_hdu.wcs.compare(wcs_header.wcs) wcs_hdu = wcs.WCS(hdulist[1]) wcs_header = wcs.WCS(hdulist[1].header) assert wcs_hdu.wcs.compare(wcs_header.wcs)
Test for #4814
def test_inconsistent_sip(): """ Test for #4814 """ hdr = get_pkg_data_contents("data/sip-broken.hdr") ctx = ctx_for_v71_dateref_warnings() with ctx: w = wcs.WCS(hdr) with pytest.warns(AstropyWarning): newhdr = w.to_header(relax=None) # CTYPE should not include "-SIP" if relax is None with ctx: wnew = wcs.WCS(newhdr) assert all(not ctyp.endswith("-SIP") for ctyp in wnew.wcs.ctype) newhdr = w.to_header(relax=False) assert "A_0_2" not in newhdr # CTYPE should not include "-SIP" if relax is False with ctx: wnew = wcs.WCS(newhdr) assert all(not ctyp.endswith("-SIP") for ctyp in wnew.wcs.ctype) with pytest.warns(AstropyWarning): newhdr = w.to_header(key="C") assert "A_0_2" not in newhdr # Test writing header with a different key with ctx: wnew = wcs.WCS(newhdr, key="C") assert all(not ctyp.endswith("-SIP") for ctyp in wnew.wcs.ctype) with pytest.warns(AstropyWarning): newhdr = w.to_header(key=" ") # Test writing a primary WCS to header with ctx: wnew = wcs.WCS(newhdr) assert all(not ctyp.endswith("-SIP") for ctyp in wnew.wcs.ctype) # Test that "-SIP" is kept into CTYPE if relax=True and # "-SIP" was in the original header newhdr = w.to_header(relax=True) with ctx: wnew = wcs.WCS(newhdr) assert all(ctyp.endswith("-SIP") for ctyp in wnew.wcs.ctype) assert "A_0_2" in newhdr # Test that SIP coefficients are also written out. assert wnew.sip is not None # ######### broken header ########### # Test that "-SIP" is added to CTYPE if relax=True and # "-SIP" was not in the original header but SIP coefficients # are present. with ctx: w = wcs.WCS(hdr) w.wcs.ctype = ["RA---TAN", "DEC--TAN"] newhdr = w.to_header(relax=True) with ctx: wnew = wcs.WCS(newhdr) assert all(ctyp.endswith("-SIP") for ctyp in wnew.wcs.ctype)
Test for #4957
def test_bounds_check(): """Test for #4957""" w = wcs.WCS(naxis=2) w.wcs.ctype = ["RA---CAR", "DEC--CAR"] w.wcs.cdelt = [10, 10] w.wcs.crval = [-90, 90] w.wcs.crpix = [1, 1] w.wcs.bounds_check(False, False) ra, dec = w.wcs_pix2world(300, 0, 0) assert_allclose(ra, -180) assert_allclose(dec, -30)
Test that when creating a WCS object using a key, CTYPE with that key is looked at and not the primary CTYPE. fix for #5443.
def test_sip_with_altkey(): """ Test that when creating a WCS object using a key, CTYPE with that key is looked at and not the primary CTYPE. fix for #5443. """ with fits.open(get_pkg_data_filename("data/sip.fits")) as f: with pytest.warns(wcs.FITSFixedWarning): w = wcs.WCS(f[0].header) # create a header with two WCSs. h1 = w.to_header(relax=True, key="A") h2 = w.to_header(relax=False) h1["CTYPE1A"] = "RA---SIN-SIP" h1["CTYPE2A"] = "DEC--SIN-SIP" h1.update(h2) with ctx_for_v71_dateref_warnings(): w = wcs.WCS(h1, key="A") assert (w.wcs.ctype == np.array(["RA---SIN-SIP", "DEC--SIN-SIP"])).all()
Test to_fits() with LookupTable distortion.
def test_to_fits_1(): """ Test to_fits() with LookupTable distortion. """ fits_name = get_pkg_data_filename("data/dist.fits") if PYTEST_LT_8_0: ctx = nullcontext() else: ctx = pytest.warns( wcs.FITSFixedWarning, match="The WCS transformation has more axes" ) with pytest.warns(AstropyDeprecationWarning), ctx: w = wcs.WCS(fits_name) wfits = w.to_fits() assert isinstance(wfits, fits.HDUList) assert isinstance(wfits[0], fits.PrimaryHDU) assert isinstance(wfits[1], fits.ImageHDU)
Test sip reading with extra key.
def test_keyedsip(): """ Test sip reading with extra key. """ hdr_name = get_pkg_data_filename("data/sip-broken.hdr") header = fits.Header.fromfile(hdr_name) del header["CRPIX1"] del header["CRPIX2"] w = wcs.WCS(header=header, key="A") assert isinstance(w.sip, wcs.Sip) assert w.sip.crpix[0] == 2048 assert w.sip.crpix[1] == 1026
Issue #7845
def test_scalar_inputs(): """ Issue #7845 """ wcsobj = wcs.WCS(naxis=1) result = wcsobj.all_pix2world(2, 1) assert_array_equal(result, [np.array(2.0)]) assert result[0].shape == () result = wcsobj.all_pix2world([2], 1) assert_array_equal(result, [np.array([2.0])]) assert result[0].shape == (1,)
Test WCS.footprint_contains(skycoord)
def test_footprint_contains(): """ Test WCS.footprint_contains(skycoord) """ header = """ WCSAXES = 2 / Number of coordinate axes CRPIX1 = 1045.0 / Pixel coordinate of reference point CRPIX2 = 1001.0 / Pixel coordinate of reference point PC1_1 = -0.00556448550786 / Coordinate transformation matrix element PC1_2 = -0.001042120133257 / Coordinate transformation matrix element PC2_1 = 0.001181477028705 / Coordinate transformation matrix element PC2_2 = -0.005590809742987 / Coordinate transformation matrix element CDELT1 = 1.0 / [deg] Coordinate increment at reference point CDELT2 = 1.0 / [deg] Coordinate increment at reference point CUNIT1 = 'deg' / Units of coordinate increment and value CUNIT2 = 'deg' / Units of coordinate increment and value CTYPE1 = 'RA---TAN' / TAN (gnomonic) projection + SIP distortions CTYPE2 = 'DEC--TAN' / TAN (gnomonic) projection + SIP distortions CRVAL1 = 250.34971683647 / [deg] Coordinate value at reference point CRVAL2 = 2.2808772582495 / [deg] Coordinate value at reference point LONPOLE = 180.0 / [deg] Native longitude of celestial pole LATPOLE = 2.2808772582495 / [deg] Native latitude of celestial pole RADESYS = 'ICRS' / Equatorial coordinate system MJD-OBS = 58612.339199259 / [d] MJD of observation matching DATE-OBS DATE-OBS= '2019-05-09T08:08:26.816Z' / ISO-8601 observation date matching MJD-OB NAXIS = 2 / NAXIS NAXIS1 = 2136 / length of first array dimension NAXIS2 = 2078 / length of second array dimension """ header = fits.Header.fromstring(header.strip(), "\n") test_wcs = wcs.WCS(header) hasCoord = test_wcs.footprint_contains(SkyCoord(254, 2, unit="deg")) assert hasCoord hasCoord = test_wcs.footprint_contains(SkyCoord(240, 2, unit="deg")) assert not hasCoord hasCoord = test_wcs.footprint_contains(SkyCoord(24, 2, unit="deg")) assert not hasCoord
Test that plate distortion model is correctly described by `wcs.to_header()` and preserved when creating a Cutout2D from the image, writing it to FITS, and reading it back from the file.
def test_distortion_header(tmp_path): """ Test that plate distortion model is correctly described by `wcs.to_header()` and preserved when creating a Cutout2D from the image, writing it to FITS, and reading it back from the file. """ path = get_pkg_data_filename("data/dss.14.29.56-62.41.05.fits.gz") cen = np.array((50, 50)) siz = np.array((20, 20)) if PYTEST_LT_8_0: ctx = nullcontext() else: ctx = pytest.warns(VerifyWarning) with fits.open(path) as hdulist: with ctx, pytest.warns(wcs.FITSFixedWarning): w = wcs.WCS(hdulist[0].header) cut = Cutout2D(hdulist[0].data, position=cen, size=siz, wcs=w) # This converts the DSS plate solution model with AMD[XY]n coefficients into a # Template Polynomial Distortion model (TPD.FWD.n coefficients); # not testing explicitly for the header keywords here. if _WCSLIB_VER < Version("7.4"): with pytest.warns( AstropyWarning, match="WCS contains a TPD distortion model in CQDIS" ): w0 = wcs.WCS(w.to_header_string()) with pytest.warns( AstropyWarning, match="WCS contains a TPD distortion model in CQDIS" ): w1 = wcs.WCS(cut.wcs.to_header_string()) if _WCSLIB_VER >= Version("7.1"): pytest.xfail("TPD coefficients incomplete with WCSLIB >= 7.1 < 7.4") else: w0 = wcs.WCS(w.to_header_string()) w1 = wcs.WCS(cut.wcs.to_header_string()) assert w.pixel_to_world(0, 0).separation(w0.pixel_to_world(0, 0)) < 1.0e-3 * u.mas assert w.pixel_to_world(*cen).separation(w0.pixel_to_world(*cen)) < 1.0e-3 * u.mas assert ( w.pixel_to_world(*cen).separation(w1.pixel_to_world(*(siz / 2))) < 1.0e-3 * u.mas ) cutfile = tmp_path / "cutout.fits" fits.writeto(cutfile, cut.data, cut.wcs.to_header()) with fits.open(cutfile) as hdulist: w2 = wcs.WCS(hdulist[0].header) assert ( w.pixel_to_world(*cen).separation(w2.pixel_to_world(*(siz / 2))) < 1.0e-3 * u.mas )
Test selection of a specific pixel list WCS using ``colsel``. See #11412.
def test_pixlist_wcs_colsel(): """ Test selection of a specific pixel list WCS using ``colsel``. See #11412. """ hdr_file = get_pkg_data_filename("data/chandra-pixlist-wcs.hdr") hdr = fits.Header.fromtextfile(hdr_file) with pytest.warns(wcs.FITSFixedWarning): w = wcs.WCS(hdr, keysel=["image", "pixel"], colsel=[11, 12]) assert w.naxis == 2 assert list(w.wcs.ctype) == ["RA---TAN", "DEC--TAN"] assert np.allclose(w.wcs.crval, [229.38051931869, -58.81108068885]) assert np.allclose(w.wcs.pc, [[1, 0], [0, 1]]) assert np.allclose(w.wcs.cdelt, [-0.00013666666666666, 0.00013666666666666]) assert np.allclose(w.wcs.lonpole, 180.0)
Issue #1960
def test_sub_segfault(): """Issue #1960""" header = fits.Header.fromtextfile(get_pkg_data_filename("data/sub-segfault.hdr")) w = wcs.WCS(header) w.sub([wcs.WCSSUB_CELESTIAL]) gc.collect()
Issue #1587
def test_wcs_sub_error_message(): """Issue #1587""" w = _wcs.Wcsprm() with pytest.raises(TypeError, match="axes must None, a sequence or an integer$"): w.sub("latitude")
Issue #3356
def test_wcs_sub(): """Issue #3356""" w = _wcs.Wcsprm() w.sub(["latitude"]) w = _wcs.Wcsprm() w.sub([b"latitude"])
Convert value to an int or an int array. Input coordinates converted to integers corresponding to the center of the pixel. The convention is that the center of the pixel is (0, 0), while the lower left corner is (-0.5, -0.5). The outputs are used to index the mask. Examples -------- >>> _toindex(np.array([-0.5, 0.49999])) array([0, 0]) >>> _toindex(np.array([0.5, 1.49999])) array([1, 1]) >>> _toindex(np.array([1.5, 2.49999])) array([2, 2])
def _toindex(value): """Convert value to an int or an int array. Input coordinates converted to integers corresponding to the center of the pixel. The convention is that the center of the pixel is (0, 0), while the lower left corner is (-0.5, -0.5). The outputs are used to index the mask. Examples -------- >>> _toindex(np.array([-0.5, 0.49999])) array([0, 0]) >>> _toindex(np.array([0.5, 1.49999])) array([1, 1]) >>> _toindex(np.array([1.5, 2.49999])) array([2, 2]) """ indx = np.asarray(np.floor(np.asarray(value) + 0.5), dtype=int) return indx
Convert the input high level object to low level values. This function uses the information in ``wcs.world_axis_object_classes`` and ``wcs.world_axis_object_components`` to convert the high level objects (such as `~.SkyCoord`) to low level "values" `~.Quantity` objects. This is used in `.HighLevelWCSMixin.world_to_pixel`, but provided as a separate function for use in other places where needed. Parameters ---------- *world_objects: object High level coordinate objects. low_level_wcs: `.BaseLowLevelWCS` The WCS object to use to interpret the coordinates.
def high_level_objects_to_values(*world_objects, low_level_wcs): """ Convert the input high level object to low level values. This function uses the information in ``wcs.world_axis_object_classes`` and ``wcs.world_axis_object_components`` to convert the high level objects (such as `~.SkyCoord`) to low level "values" `~.Quantity` objects. This is used in `.HighLevelWCSMixin.world_to_pixel`, but provided as a separate function for use in other places where needed. Parameters ---------- *world_objects: object High level coordinate objects. low_level_wcs: `.BaseLowLevelWCS` The WCS object to use to interpret the coordinates. """ # Cache the classes and components since this may be expensive serialized_classes = low_level_wcs.world_axis_object_classes components = low_level_wcs.world_axis_object_components # Deserialize world_axis_object_classes using the default order classes = OrderedDict() for key in default_order(components): if low_level_wcs.serialized_classes: classes[key] = deserialize_class(serialized_classes[key], construct=False) else: classes[key] = serialized_classes[key] # Check that the number of classes matches the number of inputs if len(world_objects) != len(classes): raise ValueError( f"Number of world inputs ({len(world_objects)}) does not match expected" f" ({len(classes)})" ) # Determine whether the classes are uniquely matched, that is we check # whether there is only one of each class. world_by_key = {} unique_match = True for w in world_objects: matches = [] for key, (klass, *_) in classes.items(): if isinstance(w, klass): matches.append(key) if len(matches) == 1: world_by_key[matches[0]] = w else: unique_match = False break # If the match is not unique, the order of the classes needs to match, # whereas if all classes are unique, we can still intelligently match # them even if the order is wrong. objects = {} if unique_match: for key, (klass, args, kwargs, *rest) in classes.items(): if len(rest) == 0: klass_gen = klass elif len(rest) == 1: klass_gen = rest[0] else: raise ValueError( "Tuples in world_axis_object_classes should have length 3 or 4" ) # FIXME: For now SkyCoord won't auto-convert upon initialization # https://github.com/astropy/astropy/issues/7689 from astropy.coordinates import SkyCoord if isinstance(world_by_key[key], SkyCoord): if "frame" in kwargs: objects[key] = world_by_key[key].transform_to(kwargs["frame"]) else: objects[key] = world_by_key[key] else: objects[key] = klass_gen(world_by_key[key], *args, **kwargs) else: for ikey, key in enumerate(classes): klass, args, kwargs, *rest = classes[key] if len(rest) == 0: klass_gen = klass elif len(rest) == 1: klass_gen = rest[0] else: raise ValueError( "Tuples in world_axis_object_classes should have length 3 or 4" ) w = world_objects[ikey] if not isinstance(w, klass): raise ValueError( "Expected the following order of world arguments:" f" {', '.join([k.__name__ for (k, *_) in classes.values()])}" ) # FIXME: For now SkyCoord won't auto-convert upon initialization # https://github.com/astropy/astropy/issues/7689 from astropy.coordinates import SkyCoord if isinstance(w, SkyCoord): if "frame" in kwargs: objects[key] = w.transform_to(kwargs["frame"]) else: objects[key] = w else: objects[key] = klass_gen(w, *args, **kwargs) # We now extract the attributes needed for the world values world = [] for key, _, attr in components: if callable(attr): world.append(attr(objects[key])) else: world.append(rec_getattr(objects[key], attr)) return world
Convert low level values into high level objects. This function uses the information in ``wcs.world_axis_object_classes`` and ``wcs.world_axis_object_components`` to convert low level "values" `~.Quantity` objects, to high level objects (such as `~.SkyCoord). This is used in `.HighLevelWCSMixin.pixel_to_world`, but provided as a separate function for use in other places where needed. Parameters ---------- *world_values: object Low level, "values" representations of the world coordinates. low_level_wcs: `.BaseLowLevelWCS` The WCS object to use to interpret the coordinates.
def values_to_high_level_objects(*world_values, low_level_wcs): """ Convert low level values into high level objects. This function uses the information in ``wcs.world_axis_object_classes`` and ``wcs.world_axis_object_components`` to convert low level "values" `~.Quantity` objects, to high level objects (such as `~.SkyCoord). This is used in `.HighLevelWCSMixin.pixel_to_world`, but provided as a separate function for use in other places where needed. Parameters ---------- *world_values: object Low level, "values" representations of the world coordinates. low_level_wcs: `.BaseLowLevelWCS` The WCS object to use to interpret the coordinates. """ # Cache the classes and components since this may be expensive components = low_level_wcs.world_axis_object_components classes = low_level_wcs.world_axis_object_classes # Deserialize classes if low_level_wcs.serialized_classes: classes_new = {} for key, value in classes.items(): classes_new[key] = deserialize_class(value, construct=False) classes = classes_new args = defaultdict(list) kwargs = defaultdict(dict) for i, (key, attr, _) in enumerate(components): if isinstance(attr, str): kwargs[key][attr] = world_values[i] else: while attr > len(args[key]) - 1: args[key].append(None) args[key][attr] = world_values[i] result = [] for key in default_order(components): klass, ar, kw, *rest = classes[key] if len(rest) == 0: klass_gen = klass elif len(rest) == 1: klass_gen = rest[0] else: raise ValueError( "Tuples in world_axis_object_classes should have length 3 or 4" ) result.append(klass_gen(*args[key], *ar, **kwargs[key], **kw)) return result
Validate a list of physical types against the UCD1+ standard.
def validate_physical_types(physical_types): """ Validate a list of physical types against the UCD1+ standard. """ for physical_type in physical_types: if ( physical_type is not None and physical_type not in VALID_UCDS and not physical_type.startswith("custom:") ): raise ValueError( f"'{physical_type}' is not a valid IOVA UCD1+ physical type. It must be" " a string specified in the list" " (http://www.ivoa.net/documents/latest/UCDlist.html) or if no" " matching type exists it can be any string prepended with 'custom:'." )
Deserialize classes recursively.
def deserialize_class(tpl, construct=True): """ Deserialize classes recursively. """ if not isinstance(tpl, tuple) or len(tpl) != 3: raise ValueError("Expected a tuple of three values") module, klass = tpl[0].rsplit(".", 1) module = importlib.import_module(module) klass = getattr(module, klass) args = tuple( deserialize_class(arg) if isinstance(arg, tuple) else arg for arg in tpl[1] ) kwargs = dict( (key, deserialize_class(val)) if isinstance(val, tuple) else (key, val) for (key, val) in tpl[2].items() ) if construct: return klass(*args, **kwargs) else: return klass, args, kwargs
Test case for issue #11446 Since we can't define a target accuracy when plotting a WCS `all_world2pix` should not error but only warn when the default accuracy can't be reached.
def test_non_convergence_warning(): """Test case for issue #11446 Since we can't define a target accuracy when plotting a WCS `all_world2pix` should not error but only warn when the default accuracy can't be reached. """ # define a minimal WCS where convergence fails for certain image positions wcs = WCS(naxis=2) crpix = [0, 0] a = b = ap = bp = np.zeros((4, 4)) a[3, 0] = -1.20116753e-07 test_pos_x = [1000, 1] test_pos_y = [0, 2] wcs.sip = Sip(a, b, ap, bp, crpix) # first make sure the WCS works when using a low accuracy expected = wcs.all_world2pix(test_pos_x, test_pos_y, 0, tolerance=1e-3) # then check that it fails when using the default accuracy with pytest.raises(NoConvergence): wcs.all_world2pix(test_pos_x, test_pos_y, 0) # at last check that world_to_pixel_values raises a warning but returns # the same 'low accuray' result with pytest.warns(UserWarning): assert_allclose(wcs.world_to_pixel_values(test_pos_x, test_pos_y), expected)
This test is a regression test for https://github.com/astropy/astropy/issues/12095 It checks the following: - If a spatial WCS isn't converted to units of deg by wcslib it still works. - If TIMESYS is upper case we parse it correctly - If a TIME CTYPE key has an algorithm code (in this case -TAB) it still works. The file used here was generated by gWCS and then edited to add the TIMESYS key.
def test_fits_tab_time_and_units(): """ This test is a regression test for https://github.com/astropy/astropy/issues/12095 It checks the following: - If a spatial WCS isn't converted to units of deg by wcslib it still works. - If TIMESYS is upper case we parse it correctly - If a TIME CTYPE key has an algorithm code (in this case -TAB) it still works. The file used here was generated by gWCS and then edited to add the TIMESYS key. """ with ( fits.open(get_pkg_data_filename("data/example_4d_tab.fits")) as hdul, pytest.warns(FITSFixedWarning), ): w = WCS(header=hdul[0].header, fobj=hdul) with warnings.catch_warnings(): warnings.filterwarnings("ignore", message=r".*dubious year \(Note \d\)") world = w.pixel_to_world(0, 0, 0, 0) assert isinstance(world[0], SkyCoord) assert world[0].data.lat.unit is u.arcsec assert world[0].data.lon.unit is u.arcsec assert u.allclose(world[0].l, 0.06475506 * u.deg) assert u.allclose(world[0].b, -0.02430561 * u.deg) assert isinstance(world[1], SpectralCoord) assert u.allclose(world[1], 24.96 * u.Hz) assert isinstance(world[2], Time) assert world[2].scale == "utc" assert u.allclose(world[2].mjd, 0.00032986111111110716)
Given a slice as input sanitise it to an easier to parse format.format. This function returns a list ``ndim`` long containing slice objects (or ints).
def sanitize_slices(slices, ndim): """ Given a slice as input sanitise it to an easier to parse format.format. This function returns a list ``ndim`` long containing slice objects (or ints). """ if not isinstance(slices, (tuple, list)): # We just have a single int slices = (slices,) if len(slices) > ndim: raise ValueError( f"The dimensionality of the specified slice {slices} can not be greater " f"than the dimensionality ({ndim}) of the wcs." ) if any(isiterable(s) for s in slices): raise IndexError( "This slice is invalid, only integer or range slices are supported." ) slices = list(slices) if Ellipsis in slices: if slices.count(Ellipsis) > 1: raise IndexError("an index can only have a single ellipsis ('...')") # Replace the Ellipsis with the correct number of slice(None)s e_ind = slices.index(Ellipsis) slices.remove(Ellipsis) n_e = ndim - len(slices) for i in range(n_e): ind = e_ind + i slices.insert(ind, slice(None)) for i in range(ndim): if i < len(slices): slc = slices[i] if isinstance(slc, slice): if slc.step and slc.step != 1: raise IndexError("Slicing WCS with a step is not supported.") elif not isinstance(slc, numbers.Integral): raise IndexError("Only integer or range slices are accepted.") else: slices.append(slice(None)) return slices
Given two slices that can be applied to a 1-d array, find the resulting slice that corresponds to the combination of both slices. We assume that slice2 can be an integer, but slice1 cannot.
def combine_slices(slice1, slice2): """ Given two slices that can be applied to a 1-d array, find the resulting slice that corresponds to the combination of both slices. We assume that slice2 can be an integer, but slice1 cannot. """ if isinstance(slice1, slice) and slice1.step is not None: raise ValueError("Only slices with steps of 1 are supported") if isinstance(slice2, slice) and slice2.step is not None: raise ValueError("Only slices with steps of 1 are supported") if isinstance(slice2, numbers.Integral): if slice1.start is None: return slice2 else: return slice2 + slice1.start if slice1.start is None: if slice1.stop is None: return slice2 else: if slice2.stop is None: return slice(slice2.start, slice1.stop) else: return slice(slice2.start, min(slice1.stop, slice2.stop)) else: if slice2.start is None: start = slice1.start else: start = slice1.start + slice2.start if slice2.stop is None: stop = slice1.stop else: if slice1.start is None: stop = slice2.stop else: stop = slice2.stop + slice1.start if slice1.stop is not None: stop = min(slice1.stop, stop) return slice(start, stop)
Render pages as a jinja template to hide/show dev docs.
def rstjinja(app, docname, source): """Render pages as a jinja template to hide/show dev docs.""" # Make sure we're outputting HTML if app.builder.format != "html": return files_to_render = ["index_dev", "install"] if docname in files_to_render: logger.info("Jinja rendering %s", docname) rendered = app.builder.templates.render_string( source[0], app.config.html_context ) source[0] = rendered
Reference targets for ``astropy:`` and ``astropy-dev:`` are special cases. Documentation links in astropy can be set up as intersphinx links so that affiliate packages do not have to override the docstrings when building the docs. If we are building the development docs it is a local ref targeting the label ``astropy-dev:<label>``, but for stable docs it should be an intersphinx resolution to the development docs. See https://github.com/astropy/astropy/issues/11366
def resolve_astropy_and_dev_reference(app, env, node, contnode): """ Reference targets for ``astropy:`` and ``astropy-dev:`` are special cases. Documentation links in astropy can be set up as intersphinx links so that affiliate packages do not have to override the docstrings when building the docs. If we are building the development docs it is a local ref targeting the label ``astropy-dev:<label>``, but for stable docs it should be an intersphinx resolution to the development docs. See https://github.com/astropy/astropy/issues/11366 """ # should the node be processed? reftarget = node.get("reftarget") # str or None if str(reftarget).startswith("astropy:"): # This allows Astropy to use intersphinx links to itself and have # them resolve to local links. Downstream packages will see intersphinx. # TODO! deprecate this if sphinx-doc/sphinx/issues/9169 is implemented. process, replace = True, "astropy:" elif dev and str(reftarget).startswith("astropy-dev:"): process, replace = True, "astropy-dev:" else: process, replace = False, "" # make link local if process: reftype = node.get("reftype") refdoc = node.get("refdoc", app.env.docname) # convert astropy intersphinx targets to local links. # there are a few types of intersphinx link patterns, as described in # https://docs.readthedocs.io/en/stable/guides/intersphinx.html reftarget = reftarget.replace(replace, "") if reftype == "doc": # also need to replace the doc link node.replace_attr("reftarget", reftarget) # Delegate to the ref node's original domain/target (typically :ref:) try: domain = app.env.domains[node["refdomain"]] return domain.resolve_xref( app.env, refdoc, app.builder, reftype, reftarget, node, contnode ) except Exception: pass
Run doctests in isolated tmp_path so outputs do not end up in repo.
def _docdir(request): """Run doctests in isolated tmp_path so outputs do not end up in repo.""" # Trigger ONLY for doctestplus doctest_plugin = request.config.pluginmanager.getplugin("doctestplus") if isinstance(request.node.parent, doctest_plugin._doctest_textfile_item_cls): # Don't apply this fixture to io.rst. It reads files and doesn't write. # Implementation from https://github.com/pytest-dev/pytest/discussions/10437 if "io.rst" not in request.node.name: old_cwd = os.getcwd() tmp_path = request.getfixturevalue("tmp_path") os.chdir(tmp_path) yield os.chdir(old_cwd) else: yield else: yield
Compute the Galactic spherical to heliocentric Sgr transformation matrix.
def galactic_to_sgr(): """Compute the Galactic spherical to heliocentric Sgr transformation matrix.""" return SGR_MATRIX
Compute the heliocentric Sgr to spherical Galactic transformation matrix.
def sgr_to_galactic(): """Compute the heliocentric Sgr to spherical Galactic transformation matrix.""" return matrix_transpose(SGR_MATRIX)
Transform a barycentric radial velocity to the Galactic Standard of Rest (GSR). The input radial velocity must be passed in as a Parameters ---------- c : `~astropy.coordinates.BaseCoordinateFrame` subclass instance The radial velocity, associated with a sky coordinates, to be transformed. v_sun : `~astropy.units.Quantity`, optional The 3D velocity of the solar system barycenter in the GSR frame. Defaults to the same solar motion as in the `~astropy.coordinates.Galactocentric` frame. Returns ------- v_gsr : `~astropy.units.Quantity` The input radial velocity transformed to a GSR frame.
def rv_to_gsr(c, v_sun=None): """Transform a barycentric radial velocity to the Galactic Standard of Rest (GSR). The input radial velocity must be passed in as a Parameters ---------- c : `~astropy.coordinates.BaseCoordinateFrame` subclass instance The radial velocity, associated with a sky coordinates, to be transformed. v_sun : `~astropy.units.Quantity`, optional The 3D velocity of the solar system barycenter in the GSR frame. Defaults to the same solar motion as in the `~astropy.coordinates.Galactocentric` frame. Returns ------- v_gsr : `~astropy.units.Quantity` The input radial velocity transformed to a GSR frame. """ if v_sun is None: v_sun = coord.Galactocentric().galcen_v_sun.to_cartesian() gal = c.transform_to(coord.Galactic) cart_data = gal.data.to_cartesian() unit_vector = cart_data / cart_data.norm() v_proj = v_sun.dot(unit_vector) return c.radial_velocity + v_proj
Dummy function to make sure docstrings don't get rendered as text
def dummy() -> None: """Dummy function to make sure docstrings don't get rendered as text"""
Convert primitive modules to float16.
def convert_module_to_f16(l): """ Convert primitive modules to float16. """ if isinstance(l, (nn.Conv1d, nn.Conv2d, nn.Conv3d)): l.weight.data = l.weight.data.half() if l.bias is not None: l.bias.data = l.bias.data.half()
Convert primitive modules to float32, undoing convert_module_to_f16().
def convert_module_to_f32(l): """ Convert primitive modules to float32, undoing convert_module_to_f16(). """ if isinstance(l, (nn.Conv1d, nn.Conv2d, nn.Conv3d)): l.weight.data = l.weight.data.float() if l.bias is not None: l.bias.data = l.bias.data.float()
Copy model parameters into a (differently-shaped) list of full-precision parameters.
def make_master_params(param_groups_and_shapes): """ Copy model parameters into a (differently-shaped) list of full-precision parameters. """ master_params = [] for param_group, shape in param_groups_and_shapes: master_param = nn.Parameter( _flatten_dense_tensors( [param.detach().float() for (_, param) in param_group] ).view(shape) ) master_param.requires_grad = True master_params.append(master_param) return master_params
Copy the gradients from the model parameters into the master parameters from make_master_params().
def model_grads_to_master_grads(param_groups_and_shapes, master_params): """ Copy the gradients from the model parameters into the master parameters from make_master_params(). """ for master_param, (param_group, shape) in zip( master_params, param_groups_and_shapes ): master_param.grad = _flatten_dense_tensors( [param_grad_or_zeros(param) for (_, param) in param_group] ).view(shape)
Copy the master parameter data back into the model parameters.
def master_params_to_model_params(param_groups_and_shapes, master_params): """ Copy the master parameter data back into the model parameters. """ # Without copying to a list, if a generator is passed, this will # silently not copy any parameters. for master_param, (param_group, _) in zip(master_params, param_groups_and_shapes): for (_, param), unflat_master_param in zip( param_group, unflatten_master_params(param_group, master_param.view(-1)) ): param.detach().copy_(unflat_master_param)
Get a pre-defined beta schedule for the given name. The beta schedule library consists of beta schedules which remain similar in the limit of num_diffusion_timesteps. Beta schedules may be added, but should not be removed or changed once they are committed to maintain backwards compatibility.
def get_named_beta_schedule(schedule_name, num_diffusion_timesteps, scale_betas=1.0): """ Get a pre-defined beta schedule for the given name. The beta schedule library consists of beta schedules which remain similar in the limit of num_diffusion_timesteps. Beta schedules may be added, but should not be removed or changed once they are committed to maintain backwards compatibility. """ if schedule_name == "linear": # Linear schedule from Ho et al, extended to work for any number of # diffusion steps. scale = scale_betas * 1000 / num_diffusion_timesteps beta_start = scale * 0.0001 beta_end = scale * 0.02 return np.linspace( beta_start, beta_end, num_diffusion_timesteps, dtype=np.float64 ) elif schedule_name == "cosine": return betas_for_alpha_bar( num_diffusion_timesteps, lambda t: math.cos((t + 0.008) / 1.008 * math.pi / 2) ** 2, ) else: raise NotImplementedError(f"unknown beta schedule: {schedule_name}")
Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of (1-beta) over time from t = [0,1]. :param num_diffusion_timesteps: the number of betas to produce. :param alpha_bar: a lambda that takes an argument t from 0 to 1 and produces the cumulative product of (1-beta) up to that part of the diffusion process. :param max_beta: the maximum beta to use; use values lower than 1 to prevent singularities.
def betas_for_alpha_bar(num_diffusion_timesteps, alpha_bar, max_beta=0.999): """ Create a beta schedule that discretizes the given alpha_t_bar function, which defines the cumulative product of (1-beta) over time from t = [0,1]. :param num_diffusion_timesteps: the number of betas to produce. :param alpha_bar: a lambda that takes an argument t from 0 to 1 and produces the cumulative product of (1-beta) up to that part of the diffusion process. :param max_beta: the maximum beta to use; use values lower than 1 to prevent singularities. """ betas = [] for i in range(num_diffusion_timesteps): t1 = i / num_diffusion_timesteps t2 = (i + 1) / num_diffusion_timesteps betas.append(min(1 - alpha_bar(t2) / alpha_bar(t1), max_beta)) return np.array(betas)
Extract values from a 1-D numpy array for a batch of indices. :param arr: the 1-D numpy array. :param timesteps: a tensor of indices into the array to extract. :param broadcast_shape: a larger shape of K dimensions with the batch dimension equal to the length of timesteps. :return: a tensor of shape [batch_size, 1, ...] where the shape has K dims.
def _extract_into_tensor(arr, timesteps, broadcast_shape): """ Extract values from a 1-D numpy array for a batch of indices. :param arr: the 1-D numpy array. :param timesteps: a tensor of indices into the array to extract. :param broadcast_shape: a larger shape of K dimensions with the batch dimension equal to the length of timesteps. :return: a tensor of shape [batch_size, 1, ...] where the shape has K dims. """ res = th.from_numpy(arr).to(device=timesteps.device)[timesteps].float() while len(res.shape) < len(broadcast_shape): res = res[..., None] return res.expand(broadcast_shape)
Compute the KL divergence between two gaussians. Shapes are automatically broadcasted, so batches can be compared to scalars, among other use cases.
def normal_kl(mean1, logvar1, mean2, logvar2): """ Compute the KL divergence between two gaussians. Shapes are automatically broadcasted, so batches can be compared to scalars, among other use cases. """ tensor = None for obj in (mean1, logvar1, mean2, logvar2): if isinstance(obj, th.Tensor): tensor = obj break assert tensor is not None, "at least one argument must be a Tensor" # Force variances to be Tensors. Broadcasting helps convert scalars to # Tensors, but it does not work for th.exp(). logvar1, logvar2 = [ x if isinstance(x, th.Tensor) else th.tensor(x).to(tensor) for x in (logvar1, logvar2) ] return 0.5 * ( -1.0 + logvar2 - logvar1 + th.exp(logvar1 - logvar2) + ((mean1 - mean2) ** 2) * th.exp(-logvar2) )
A fast approximation of the cumulative distribution function of the standard normal.
def approx_standard_normal_cdf(x): """ A fast approximation of the cumulative distribution function of the standard normal. """ return 0.5 * (1.0 + th.tanh(np.sqrt(2.0 / np.pi) * (x + 0.044715 * th.pow(x, 3))))
Compute the log-likelihood of a Gaussian distribution discretizing to a given image. :param x: the target images. It is assumed that this was uint8 values, rescaled to the range [-1, 1]. :param means: the Gaussian mean Tensor. :param log_scales: the Gaussian log stddev Tensor. :return: a tensor like x of log probabilities (in nats).
def discretized_gaussian_log_likelihood(x, *, means, log_scales): """ Compute the log-likelihood of a Gaussian distribution discretizing to a given image. :param x: the target images. It is assumed that this was uint8 values, rescaled to the range [-1, 1]. :param means: the Gaussian mean Tensor. :param log_scales: the Gaussian log stddev Tensor. :return: a tensor like x of log probabilities (in nats). """ assert x.shape == means.shape == log_scales.shape centered_x = x - means inv_stdv = th.exp(-log_scales) plus_in = inv_stdv * (centered_x + 1.0 / 255.0) cdf_plus = approx_standard_normal_cdf(plus_in) min_in = inv_stdv * (centered_x - 1.0 / 255.0) cdf_min = approx_standard_normal_cdf(min_in) log_cdf_plus = th.log(cdf_plus.clamp(min=1e-12)) log_one_minus_cdf_min = th.log((1.0 - cdf_min).clamp(min=1e-12)) cdf_delta = cdf_plus - cdf_min log_probs = th.where( x < -0.999, log_cdf_plus, th.where(x > 0.999, log_one_minus_cdf_min, th.log(cdf_delta.clamp(min=1e-12))), ) assert log_probs.shape == x.shape return log_probs
Create a 1D, 2D, or 3D convolution module.
def conv_nd(dims, *args, **kwargs): """ Create a 1D, 2D, or 3D convolution module. """ if dims == 1: return nn.Conv1d(*args, **kwargs) elif dims == 2: return nn.Conv2d(*args, **kwargs) elif dims == 3: return nn.Conv3d(*args, **kwargs) raise ValueError(f"unsupported dimensions: {dims}")
Create a linear module.
def linear(*args, **kwargs): """ Create a linear module. """ return nn.Linear(*args, **kwargs)
Create a 1D, 2D, or 3D average pooling module.
def avg_pool_nd(dims, *args, **kwargs): """ Create a 1D, 2D, or 3D average pooling module. """ if dims == 1: return nn.AvgPool1d(*args, **kwargs) elif dims == 2: return nn.AvgPool2d(*args, **kwargs) elif dims == 3: return nn.AvgPool3d(*args, **kwargs) raise ValueError(f"unsupported dimensions: {dims}")
Update target parameters to be closer to those of source parameters using an exponential moving average. :param target_params: the target parameter sequence. :param source_params: the source parameter sequence. :param rate: the EMA rate (closer to 1 means slower).
def update_ema(target_params, source_params, rate=0.99): """ Update target parameters to be closer to those of source parameters using an exponential moving average. :param target_params: the target parameter sequence. :param source_params: the source parameter sequence. :param rate: the EMA rate (closer to 1 means slower). """ for targ, src in zip(target_params, source_params): targ.detach().mul_(rate).add_(src, alpha=1 - rate)
Zero out the parameters of a module and return it.
def zero_module(module): """ Zero out the parameters of a module and return it. """ for p in module.parameters(): p.detach().zero_() return module
Scale the parameters of a module and return it.
def scale_module(module, scale): """ Scale the parameters of a module and return it. """ for p in module.parameters(): p.detach().mul_(scale) return module
Take the mean over all non-batch dimensions.
def mean_flat(tensor): """ Take the mean over all non-batch dimensions. """ return tensor.mean(dim=list(range(1, len(tensor.shape))))
Take the sum over all non-batch dimensions.
def sum_flat(tensor): """ Take the sum over all non-batch dimensions. """ return tensor.sum(dim=list(range(1, len(tensor.shape))))
Make a standard normalization layer. :param channels: number of input channels. :return: an nn.Module for normalization.
def normalization(channels): """ Make a standard normalization layer. :param channels: number of input channels. :return: an nn.Module for normalization. """ return GroupNorm32(32, channels)
Create sinusoidal timestep embeddings. :param timesteps: a 1-D Tensor of N indices, one per batch element. These may be fractional. :param dim: the dimension of the output. :param max_period: controls the minimum frequency of the embeddings. :return: an [N x dim] Tensor of positional embeddings.
def timestep_embedding(timesteps, dim, max_period=10000): """ Create sinusoidal timestep embeddings. :param timesteps: a 1-D Tensor of N indices, one per batch element. These may be fractional. :param dim: the dimension of the output. :param max_period: controls the minimum frequency of the embeddings. :return: an [N x dim] Tensor of positional embeddings. """ half = dim // 2 freqs = th.exp( -math.log(max_period) * th.arange(start=0, end=half, dtype=th.float32) / half ).to(device=timesteps.device) args = timesteps[:, None].float() * freqs[None] embedding = th.cat([th.cos(args), th.sin(args)], dim=-1) if dim % 2: embedding = th.cat([embedding, th.zeros_like(embedding[:, :1])], dim=-1) return embedding
Evaluate a function without caching intermediate activations, allowing for reduced memory at the expense of extra compute in the backward pass. :param func: the function to evaluate. :param inputs: the argument sequence to pass to `func`. :param params: a sequence of parameters `func` depends on but does not explicitly take as arguments. :param flag: if False, disable gradient checkpointing.
def checkpoint(func, inputs, params, flag): """ Evaluate a function without caching intermediate activations, allowing for reduced memory at the expense of extra compute in the backward pass. :param func: the function to evaluate. :param inputs: the argument sequence to pass to `func`. :param params: a sequence of parameters `func` depends on but does not explicitly take as arguments. :param flag: if False, disable gradient checkpointing. """ if flag: args = tuple(inputs) + tuple(params) return CheckpointFunction.apply(func, len(inputs), *args) else: return func(*inputs)
Create a ScheduleSampler from a library of pre-defined samplers. :param name: the name of the sampler. :param diffusion: the diffusion object to sample for.
def create_named_schedule_sampler(name, diffusion): """ Create a ScheduleSampler from a library of pre-defined samplers. :param name: the name of the sampler. :param diffusion: the diffusion object to sample for. """ if name == "uniform": return UniformSampler(diffusion) elif name == "loss-second-moment": return LossSecondMomentResampler(diffusion) else: raise NotImplementedError(f"unknown schedule sampler: {name}")
Create a list of timesteps to use from an original diffusion process, given the number of timesteps we want to take from equally-sized portions of the original process. For example, if there's 300 timesteps and the section counts are [10,15,20] then the first 100 timesteps are strided to be 10 timesteps, the second 100 are strided to be 15 timesteps, and the final 100 are strided to be 20. If the stride is a string starting with "ddim", then the fixed striding from the DDIM paper is used, and only one section is allowed. :param num_timesteps: the number of diffusion steps in the original process to divide up. :param section_counts: either a list of numbers, or a string containing comma-separated numbers, indicating the step count per section. As a special case, use "ddimN" where N is a number of steps to use the striding from the DDIM paper. :return: a set of diffusion steps from the original process to use.
def space_timesteps(num_timesteps, section_counts): """ Create a list of timesteps to use from an original diffusion process, given the number of timesteps we want to take from equally-sized portions of the original process. For example, if there's 300 timesteps and the section counts are [10,15,20] then the first 100 timesteps are strided to be 10 timesteps, the second 100 are strided to be 15 timesteps, and the final 100 are strided to be 20. If the stride is a string starting with "ddim", then the fixed striding from the DDIM paper is used, and only one section is allowed. :param num_timesteps: the number of diffusion steps in the original process to divide up. :param section_counts: either a list of numbers, or a string containing comma-separated numbers, indicating the step count per section. As a special case, use "ddimN" where N is a number of steps to use the striding from the DDIM paper. :return: a set of diffusion steps from the original process to use. """ if isinstance(section_counts, str): if section_counts.startswith("ddim"): desired_count = int(section_counts[len("ddim") :]) for i in range(1, num_timesteps): if len(range(0, num_timesteps, i)) == desired_count: return set(range(0, num_timesteps, i)) raise ValueError( f"cannot create exactly {num_timesteps} steps with an integer stride" ) section_counts = [int(x) for x in section_counts.split(",")] size_per = num_timesteps // len(section_counts) extra = num_timesteps % len(section_counts) start_idx = 0 all_steps = [] for i, section_count in enumerate(section_counts): size = size_per + (1 if i < extra else 0) if size < section_count: raise ValueError( f"cannot divide section of {size} steps into {section_count}" ) if section_count <= 1: frac_stride = 1 else: frac_stride = (size - 1) / (section_count - 1) cur_idx = 0.0 taken_steps = [] for _ in range(section_count): taken_steps.append(start_idx + round(cur_idx)) cur_idx += frac_stride all_steps += taken_steps start_idx += size return set(all_steps)
Take the sum over all non-batch dimensions.
def sum_flat(tensor): """ Take the sum over all non-batch dimensions. """ return tensor.sum(dim=list(range(1, len(tensor.shape))))
Parse filenames of the form path/to/modelNNNNNN.pt, where NNNNNN is the checkpoint's number of steps.
def parse_resume_step_from_filename(filename): """ Parse filenames of the form path/to/modelNNNNNN.pt, where NNNNNN is the checkpoint's number of steps. """ split = filename.split("model") if len(split) < 2: return 0 split1 = split[-1].split(".")[0] try: return int(split1) except ValueError: return 0
Log a value of some diagnostic Call this once for each diagnostic quantity, each iteration If called many times, last value will be used.
def logkv(key, val): """ Log a value of some diagnostic Call this once for each diagnostic quantity, each iteration If called many times, last value will be used. """ get_current().logkv(key, val)
The same as logkv(), but if called many times, values averaged.
def logkv_mean(key, val): """ The same as logkv(), but if called many times, values averaged. """ get_current().logkv_mean(key, val)
Log a dictionary of key-value pairs
def logkvs(d): """ Log a dictionary of key-value pairs """ for k, v in d.items(): logkv(k, v)
Write all of the diagnostics from the current iteration
def dumpkvs(): """ Write all of the diagnostics from the current iteration """ return get_current().dumpkvs()
Write the sequence of args, with no separators, to the console and output files (if you've configured an output file).
def log(*args, level=INFO): """ Write the sequence of args, with no separators, to the console and output files (if you've configured an output file). """ get_current().log(*args, level=level)
Set logging threshold on current logger.
def set_level(level): """ Set logging threshold on current logger. """ get_current().set_level(level)