simple-squiggle/node_modules/mathjs/lib/esm/function/arithmetic/log2.js

71 lines
2.0 KiB
JavaScript

import { factory } from '../../utils/factory.js';
import { deepMap } from '../../utils/collection.js';
import { log2Number } from '../../plain/number/index.js';
var name = 'log2';
var dependencies = ['typed', 'config', 'Complex'];
export var createLog2 = /* #__PURE__ */factory(name, dependencies, _ref => {
var {
typed,
config,
Complex
} = _ref;
/**
* Calculate the 2-base of a value. This is the same as calculating `log(x, 2)`.
*
* For matrices, the function is evaluated element wise.
*
* Syntax:
*
* math.log2(x)
*
* Examples:
*
* math.log2(0.03125) // returns -5
* math.log2(16) // returns 4
* math.log2(16) / math.log2(2) // returns 4
* math.pow(2, 4) // returns 16
*
* See also:
*
* exp, log, log1p, log10
*
* @param {number | BigNumber | Complex | Array | Matrix} x
* Value for which to calculate the logarithm.
* @return {number | BigNumber | Complex | Array | Matrix}
* Returns the 2-base logarithm of `x`
*/
return typed(name, {
number: function number(x) {
if (x >= 0 || config.predictable) {
return log2Number(x);
} else {
// negative value -> complex value computation
return _log2Complex(new Complex(x, 0));
}
},
Complex: _log2Complex,
BigNumber: function BigNumber(x) {
if (!x.isNegative() || config.predictable) {
return x.log(2);
} else {
// downgrade to number, return Complex valued result
return _log2Complex(new Complex(x.toNumber(), 0));
}
},
'Array | Matrix': function ArrayMatrix(x) {
return deepMap(x, this);
}
});
/**
* Calculate log2 for a complex value
* @param {Complex} x
* @returns {Complex}
* @private
*/
function _log2Complex(x) {
var newX = Math.sqrt(x.re * x.re + x.im * x.im);
return new Complex(Math.log2 ? Math.log2(newX) : Math.log(newX) / Math.LN2, Math.atan2(x.im, x.re) / Math.LN2);
}
});