19 lines
515 B
JavaScript
19 lines
515 B
JavaScript
// Parts of implementation taken from es6-shim project
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// See: https://github.com/paulmillr/es6-shim/blob/master/es6-shim.js
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"use strict";
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var expm1 = require("../expm1")
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, abs = Math.abs
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, exp = Math.exp
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, e = Math.E;
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module.exports = function (value) {
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if (isNaN(value)) return NaN;
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value = Number(value);
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if (value === 0) return value;
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if (!isFinite(value)) return value;
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if (abs(value) < 1) return (expm1(value) - expm1(-value)) / 2;
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return (exp(value - 1) - exp(-value - 1)) * e / 2;
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};
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