125 lines
3.0 KiB
JavaScript
125 lines
3.0 KiB
JavaScript
import { factory } from '../../utils/factory.js';
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import { arraySize } from '../../utils/array.js';
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import { isMatrix } from '../../utils/is.js';
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import { IndexError } from '../../error/IndexError.js';
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var name = 'apply';
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var dependencies = ['typed', 'isInteger'];
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export var createApply = /* #__PURE__ */factory(name, dependencies, _ref => {
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var {
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typed,
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isInteger
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} = _ref;
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/**
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* Apply a function that maps an array to a scalar
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* along a given axis of a matrix or array.
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* Returns a new matrix or array with one less dimension than the input.
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*
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* Syntax:
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*
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* math.apply(A, dim, callback)
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*
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* Where:
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*
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* - `dim: number` is a zero-based dimension over which to concatenate the matrices.
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*
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* Examples:
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*
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* const A = [[1, 2], [3, 4]]
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* const sum = math.sum
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*
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* math.apply(A, 0, sum) // returns [4, 6]
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* math.apply(A, 1, sum) // returns [3, 7]
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*
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* See also:
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*
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* map, filter, forEach
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*
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* @param {Array | Matrix} array The input Matrix
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* @param {number} dim The dimension along which the callback is applied
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* @param {Function} callback The callback function that is applied. This Function
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* should take an array or 1-d matrix as an input and
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* return a number.
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* @return {Array | Matrix} res The residual matrix with the function applied over some dimension.
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*/
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return typed(name, {
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'Array | Matrix, number | BigNumber, function': function ArrayMatrixNumberBigNumberFunction(mat, dim, callback) {
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if (!isInteger(dim)) {
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throw new TypeError('Integer number expected for dimension');
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}
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var size = Array.isArray(mat) ? arraySize(mat) : mat.size();
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if (dim < 0 || dim >= size.length) {
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throw new IndexError(dim, size.length);
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}
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if (isMatrix(mat)) {
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return mat.create(_apply(mat.valueOf(), dim, callback));
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} else {
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return _apply(mat, dim, callback);
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}
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}
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});
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});
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/**
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* Recursively reduce a matrix
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* @param {Array} mat
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* @param {number} dim
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* @param {Function} callback
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* @returns {Array} ret
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* @private
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*/
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function _apply(mat, dim, callback) {
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var i, ret, tran;
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if (dim <= 0) {
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if (!Array.isArray(mat[0])) {
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return callback(mat);
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} else {
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tran = _switch(mat);
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ret = [];
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for (i = 0; i < tran.length; i++) {
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ret[i] = _apply(tran[i], dim - 1, callback);
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}
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return ret;
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}
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} else {
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ret = [];
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for (i = 0; i < mat.length; i++) {
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ret[i] = _apply(mat[i], dim - 1, callback);
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}
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return ret;
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}
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}
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/**
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* Transpose a matrix
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* @param {Array} mat
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* @returns {Array} ret
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* @private
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*/
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function _switch(mat) {
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var I = mat.length;
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var J = mat[0].length;
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var i, j;
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var ret = [];
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for (j = 0; j < J; j++) {
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var tmp = [];
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for (i = 0; i < I; i++) {
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tmp.push(mat[i][j]);
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}
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ret.push(tmp);
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}
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return ret;
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} |