mathjs/lib/esm/type/matrix/utils/matAlgo07xSSf.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif

import { factory } from '../../../utils/factory.js';
import { DimensionError } from '../../../error/DimensionError.js';
var name = 'matAlgo07xSSf';
var dependencies = ['typed', 'SparseMatrix'];
export var createMatAlgo07xSSf = /* #__PURE__ */factory(name, dependencies, _ref => {
  var {
    typed,
    SparseMatrix
  } = _ref;
  /**
  * Iterates over SparseMatrix A and SparseMatrix B items (zero and nonzero) and invokes the callback function f(Aij, Bij).
  * Callback function invoked MxN times.
  *
  * C(i,j) = f(Aij, Bij)
  *
  * @param {Matrix}   a                 The SparseMatrix instance (A)
  * @param {Matrix}   b                 The SparseMatrix instance (B)
  * @param {Function} callback          The f(Aij,Bij) operation to invoke
  *
  * @return {Matrix}                    SparseMatrix (C)
  *
  * see https://github.com/josdejong/mathjs/pull/346#issuecomment-97620294
  */
  return function matAlgo07xSSf(a, b, callback) {
    // sparse matrix arrays
    var asize = a._size;
    var adt = a._datatype || a._data === undefined ? a._datatype : a.getDataType();
    var bsize = b._size;
    var bdt = b._datatype || b._data === undefined ? b._datatype : b.getDataType();

    // validate dimensions
    if (asize.length !== bsize.length) {
      throw new DimensionError(asize.length, bsize.length);
    }
    if (asize[0] !== bsize[0] || asize[1] !== bsize[1]) {
      throw new RangeError('Dimension mismatch. Matrix A (' + asize + ') must match Matrix B (' + bsize + ')');
    }

    // rows & columns
    var rows = asize[0];
    var columns = asize[1];

    // datatype
    var dt;
    var zero = 0;
    var cf = callback;

    // process data types
    if (typeof adt === 'string' && adt === bdt && adt !== 'mixed') {
      dt = adt;
      zero = typed.convert(0, dt);
      cf = typed.find(callback, [dt, dt]);
    }

    // result arrays for sparse format
    var cvalues = [];
    var cindex = [];
    var cptr = new Array(columns + 1).fill(0); // Start with column pointer array

    // workspaces
    var xa = [];
    var xb = [];
    var wa = [];
    var wb = [];

    // loop columns
    for (var j = 0; j < columns; j++) {
      var mark = j + 1;
      var nonZeroCount = 0;
      _scatter(a, j, wa, xa, mark);
      _scatter(b, j, wb, xb, mark);

      // loop rows
      for (var i = 0; i < rows; i++) {
        var va = wa[i] === mark ? xa[i] : zero;
        var vb = wb[i] === mark ? xb[i] : zero;

        // invoke callback
        var cij = cf(va, vb);
        // Store all non zero and true values
        if (cij !== 0 && cij !== false) {
          cindex.push(i); // row index
          cvalues.push(cij); // computed value
          nonZeroCount++;
        }
      }

      // Update column pointer with cumulative count of non-zero values
      cptr[j + 1] = cptr[j] + nonZeroCount;
    }

    // Return the result as a sparse matrix
    return new SparseMatrix({
      values: cvalues,
      index: cindex,
      ptr: cptr,
      size: [rows, columns],
      datatype: adt === a._datatype && bdt === b._datatype ? dt : undefined
    });
  };
  function _scatter(m, j, w, x, mark) {
    // a arrays
    var values = m._values;
    var index = m._index;
    var ptr = m._ptr;
    // loop values in column j
    for (var k = ptr[j], k1 = ptr[j + 1]; k < k1; k++) {
      // row
      var i = index[k];
      // update workspace
      w[i] = mark;
      x[i] = values[k];
    }
  }
});