58 lines
1.3 KiB
JavaScript
58 lines
1.3 KiB
JavaScript
import {bisect} from "d3-array";
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import {slice} from "./array";
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import {linearish} from "./linear";
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import {initRange} from "./init";
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export default function quantize() {
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var x0 = 0,
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x1 = 1,
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n = 1,
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domain = [0.5],
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range = [0, 1],
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unknown;
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function scale(x) {
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return x <= x ? range[bisect(domain, x, 0, n)] : unknown;
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}
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function rescale() {
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var i = -1;
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domain = new Array(n);
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while (++i < n) domain[i] = ((i + 1) * x1 - (i - n) * x0) / (n + 1);
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return scale;
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}
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scale.domain = function(_) {
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return arguments.length ? (x0 = +_[0], x1 = +_[1], rescale()) : [x0, x1];
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};
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scale.range = function(_) {
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return arguments.length ? (n = (range = slice.call(_)).length - 1, rescale()) : range.slice();
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};
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scale.invertExtent = function(y) {
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var i = range.indexOf(y);
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return i < 0 ? [NaN, NaN]
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: i < 1 ? [x0, domain[0]]
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: i >= n ? [domain[n - 1], x1]
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: [domain[i - 1], domain[i]];
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};
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scale.unknown = function(_) {
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return arguments.length ? (unknown = _, scale) : scale;
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};
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scale.thresholds = function() {
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return domain.slice();
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};
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scale.copy = function() {
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return quantize()
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.domain([x0, x1])
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.range(range)
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.unknown(unknown);
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};
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return initRange.apply(linearish(scale), arguments);
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}
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