mathjs/lib/cjs/function/matrix/column.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createColumn = void 0;

var _factory = require("../../utils/factory.js");

var _object = require("../../utils/object.js");

var _array = require("../../utils/array.js");

var name = 'column';
var dependencies = ['typed', 'Index', 'matrix', 'range'];
var createColumn = /* #__PURE__ */(0, _factory.factory)(name, dependencies, function (_ref) {
  var typed = _ref.typed,
      Index = _ref.Index,
      matrix = _ref.matrix,
      range = _ref.range;

  /**
   * Return a column from a Matrix.
   *
   * Syntax:
   *
   *     math.column(value, index)
   *
   * Example:
   *
   *     // get a column
   *     const d = [[1, 2], [3, 4]]
   *     math.column(d, 1) // returns [[2], [4]]
   *
   * See also:
   *
   *     row
   *
   * @param {Array | Matrix } value   An array or matrix
   * @param {number} column           The index of the column
   * @return {Array | Matrix}         The retrieved column
   */
  return typed(name, {
    'Matrix, number': _column,
    'Array, number': function ArrayNumber(value, column) {
      return _column(matrix((0, _object.clone)(value)), column).valueOf();
    }
  });
  /**
   * Retrieve a column of a matrix
   * @param {Matrix } value  A matrix
   * @param {number} column  The index of the column
   * @return {Matrix}        The retrieved column
   */

  function _column(value, column) {
    // check dimensions
    if (value.size().length !== 2) {
      throw new Error('Only two dimensional matrix is supported');
    }

    (0, _array.validateIndex)(column, value.size()[1]);
    var rowRange = range(0, value.size()[0]);
    var index = new Index(rowRange, column);
    return value.subset(index);
  }
});
exports.createColumn = createColumn;