mathjs/lib/function/algebra/sparse/cs_ipvec.js

'use strict';

function factory () {

  /**
   * Permutes a vector; x = P'b. In MATLAB notation, x(p)=b.
   *
   * @param {Array} p           The permutation vector of length n. null value denotes identity
   * @param {Array} b           The input vector
   *
   * @return {Array}            The output vector x = P'b
   */
  var cs_ipvec = function (p, b, n) {
    // vars 
    var k;
    var n = b.length;
    var x = [];
    // check permutation vector was provided, p = null denotes identity
    if (p) {
      // loop vector
      for (k = 0; k < n; k++) {
        // apply permutation
        x[p[k]] = b[k];
      }
    }
    else {
      // loop vector
      for (k = 0; k < n; k++) {
        // x[i] = b[i]
        x[k] = b[k];
      }
    }
    return x;
  };

  return cs_ipvec;
}

exports.name = 'cs_ipvec';
exports.path = 'sparse';
exports.factory = factory;