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""" |
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Checkout https://awesome-panel.org/resources/lonboard_dashboard/ |
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""" |
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import colorcet as cc |
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import geopandas as gpd |
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from lonboard import Map, PathLayer |
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from lonboard.colormap import apply_continuous_cmap |
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from palettable.palette import Palette |
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import panel as pn |
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url = "https://naciscdn.org/naturalearth/10m/cultural/ne_10m_roads_north_america.zip" |
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path = "ne_10m_roads_north_america.zip" |
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try: |
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gdf = pn.state.as_cached( |
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"ne_10m_roads_north_america", gpd.read_file, filename=path, engine="pyogrio" |
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) |
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except: |
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gdf = pn.state.as_cached( |
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"ne_10m_roads_north_america", gpd.read_file, filename=url, engine="pyogrio" |
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) |
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state_options = sorted(state for state in gdf["state"].unique() if state) |
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def to_rgb(hex: str) -> list: |
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h = hex.strip("#") |
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return list(int(h[i : i + 2], 16) for i in (0, 2, 4)) |
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def to_palette(cmap) -> Palette: |
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"""Returns the ColorCet colormap as a palettable Palette""" |
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colors = [to_rgb(item) for item in cmap] |
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return Palette(name="colorcet", map_type="colorcet", colors=colors) |
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def create_map(state="California", cmap=cc.fire, alpha=0.8): |
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palette = to_palette(cmap) |
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data = gdf[gdf["state"] == state] |
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layer = PathLayer.from_geopandas(data, width_min_pixels=0.8) |
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normalized_scale_rank = (data["scalerank"] - 3) / 9 |
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layer.get_color = apply_continuous_cmap(normalized_scale_rank, palette, alpha=alpha) |
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map_ = Map(layers=[layer], _height=650) |
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return map_ |
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description = """# lonboard |
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A Python library for **fast, interactive geospatial vector data visualization** in Jupyter (and Panel). |
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By utilizing new technologies like `GeoArrow` and `GeoParquet` in conjunction with GPU-based map rendering, lonboard aims to enable visualizing large geospatial datasets interactively through a simple interface.""" |
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pn.extension("ipywidgets") |
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state = pn.widgets.Select( |
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value="California", |
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options=state_options, |
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width=150, |
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name="State", |
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sizing_mode="stretch_width", |
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) |
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cmap = pn.widgets.ColorMap( |
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value=cc.fire, |
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options=cc.palette, |
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ncols=3, |
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swatch_width=100, |
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name="cmap by Colorcet", |
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sizing_mode="stretch_width", |
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) |
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alpha = pn.widgets.FloatSlider( |
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value=0.8, start=0, end=1, name="Alpha", min_width=100, sizing_mode="stretch_width" |
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) |
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logo = pn.pane.Image( |
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"https://github.com/developmentseed/lonboard/raw/main/assets/dalle-lonboard.jpg" |
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) |
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def title(state): |
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return f"# North America Roads: {state}" |
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|
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settings = pn.Column(state, cmap, alpha) |
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description = pn.Column(pn.pane.Markdown(description, margin=5), logo) |
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component = pn.Column( |
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pn.bind(title, state=state), |
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pn.panel( |
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pn.bind(create_map, state=state, cmap=cmap, alpha=alpha.param.value_throttled), |
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sizing_mode="stretch_both", |
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), |
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sizing_mode="stretch_both", |
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) |
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pn.template.FastListTemplate( |
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logo="https://panel.holoviz.org/_static/logo_horizontal_dark_theme.png", |
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title="Works with LonBoard", |
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main=[component], |
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sidebar=[description, settings], |
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).servable() |
