File size: 1,183 Bytes
bc20498 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 |
import {linearish} from "./linear.js";
import {copy, identity, transformer} from "./continuous.js";
import {initRange} from "./init.js";
function transformPow(exponent) {
return function(x) {
return x < 0 ? -Math.pow(-x, exponent) : Math.pow(x, exponent);
};
}
function transformSqrt(x) {
return x < 0 ? -Math.sqrt(-x) : Math.sqrt(x);
}
function transformSquare(x) {
return x < 0 ? -x * x : x * x;
}
export function powish(transform) {
var scale = transform(identity, identity),
exponent = 1;
function rescale() {
return exponent === 1 ? transform(identity, identity)
: exponent === 0.5 ? transform(transformSqrt, transformSquare)
: transform(transformPow(exponent), transformPow(1 / exponent));
}
scale.exponent = function(_) {
return arguments.length ? (exponent = +_, rescale()) : exponent;
};
return linearish(scale);
}
export default function pow() {
var scale = powish(transformer());
scale.copy = function() {
return copy(scale, pow()).exponent(scale.exponent());
};
initRange.apply(scale, arguments);
return scale;
}
export function sqrt() {
return pow.apply(null, arguments).exponent(0.5);
}
|