2015-04-24 11:13:17 -04:00

695 lines
18 KiB
JavaScript

'use strict';
var util = require('../../util/index');
var array = util.array;
function factory (type, config, load, typed) {
var matrix = load(require('../construction/matrix'));
var add = load(require('./add'));
var equal = load(require('../relational/equal'));
var collection = load(require('../../type/collection'));
var DenseMatrix = type.DenseMatrix;
var SparseMatrix = type.SparseMatrix;
var Spa = type.Spa;
/**
* Multiply two values, `x * y`. The result is squeezed.
* For matrices, the matrix product is calculated.
*
* Syntax:
*
* math.multiply(x, y)
*
* Examples:
*
* math.multiply(4, 5.2); // returns Number 20.8
*
* var a = math.complex(2, 3);
* var b = math.complex(4, 1);
* math.multiply(a, b); // returns Complex 5 + 14i
*
* var c = [[1, 2], [4, 3]];
* var d = [[1, 2, 3], [3, -4, 7]];
* math.multiply(c, d); // returns Array [[7, -6, 17], [13, -4, 33]]
*
* var e = math.unit('2.1 km');
* math.multiply(3, e); // returns Unit 6.3 km
*
* See also:
*
* divide
*
* @param {Number | BigNumber | Boolean | Complex | Unit | Array | Matrix | null} x First value to multiply
* @param {Number | BigNumber | Boolean | Complex | Unit | Array | Matrix | null} y Second value to multiply
* @return {Number | BigNumber | Complex | Unit | Array | Matrix} Multiplication of `x` and `y`
*/
var multiply = typed('multiply', {
'number, number': function (x, y) {
return x * y;
},
'BigNumber, BigNumber': function (x, y) {
return x.times(y);
},
'Complex, Complex': function (x, y) {
return new type.Complex(
x.re * y.re - x.im * y.im,
x.re * y.im + x.im * y.re
);
},
'number, Unit': function (x, y) {
var res = y.clone();
res.value = (res.value === null) ? res._normalize(x) : (res.value * x);
return res;
},
'Unit, number': function (x, y) {
var res = x.clone();
res.value = (res.value === null) ? res._normalize(y) : (res.value * y);
return res;
},
'Array, Array': function (x, y) {
// check dimensions
_validateMatrixDimensions(array.size(x), array.size(y));
// use dense matrix implementation
var m = multiply(matrix(x), matrix(y));
// return array or scalar
return m instanceof type.Matrix ? m.valueOf() : m;
},
'Matrix, Matrix': function (x, y) {
// dimensions
var xsize = x.size();
var ysize = y.size();
// check dimensions
_validateMatrixDimensions(xsize, ysize);
// process dimensions
if (xsize.length === 1) {
// process y dimensions
if (ysize.length === 1) {
// Vector * Vector
return _multiplyVectorVector(x, y, xsize[0]);
}
// Vector * Matrix
return _multiplyVectorMatrix(x, y);
}
// process y dimensions
if (ysize.length === 1) {
// Matrix * Vector
return _multiplyMatrixVector(x, y);
}
// Matrix * Matrix
return _multiplyMatrixMatrix(x, y);
},
'Matrix, Array': function (x, y) {
// use Matrix * Matrix implementation
return multiply(x, matrix(y));
},
'Array, Matrix': function (x, y) {
// use Matrix * Matrix implementation
return multiply(matrix(x, y.storage()), y);
},
'Array, any': function (x, y) {
return collection.deepMap2(x, y, multiply);
},
'Matrix, any': function (x, y) {
// use matrix map, skip zeros since 0 * X = 0
return x.map(function (v) {
return multiply(v, y);
}, true);
},
'any, Array | Matrix': function (x, y) {
// use matrix map, skip zeros since 0 * X = 0
return y.map(function (v) {
return multiply(v, x);
}, true);
}
});
var _validateMatrixDimensions = function (size1, size2) {
// check left operand dimensions
switch (size1.length) {
case 1:
// check size2
switch (size2.length) {
case 1:
// Vector x Vector
if (size1[0] !== size2[0]) {
// throw error
throw new RangeError('Dimension mismatch in multiplication. Vectors must have the same length');
}
break;
case 2:
// Vector x Matrix
if (size1[0] !== size2[0]) {
// throw error
throw new RangeError('Dimension mismatch in multiplication. Vector length (' + size1[0] + ') must match Matrix rows (' + size2[0] + ')');
}
break;
default:
throw new Error('Can only multiply a 1 or 2 dimensional matrix (Matrix B has ' + size2.length + ' dimensions)');
}
break;
case 2:
// check size2
switch (size2.length) {
case 1:
// Matrix x Vector
if (size1[1] !== size2[0]) {
// throw error
throw new RangeError('Dimension mismatch in multiplication. Matrix columns (' + size1[1] + ') must match Vector length (' + size2[0] + ')');
}
break;
case 2:
// Matrix x Matrix
if (size1[1] !== size2[0]) {
// throw error
throw new RangeError('Dimension mismatch in multiplication. Matrix A columns (' + size1[1] + ') must match Matrix B rows (' + size2[0] + ')');
}
break;
default:
throw new Error('Can only multiply a 1 or 2 dimensional matrix (Matrix B has ' + size2.length + ' dimensions)');
}
break;
default:
throw new Error('Can only multiply a 1 or 2 dimensional matrix (Matrix A has ' + size1.length + ' dimensions)');
}
};
/**
* C = A * B
*
* @param {Matrix} a Dense Vector (N)
* @param {Matrix} b Dense Vector (N)
*
* @return {Number} Scalar value
*/
var _multiplyVectorVector = function (a, b, n) {
// check empty vector
if (n === 0)
throw new Error('Cannot multiply two empty vectors');
// a dense
var adata = a._data;
// b dense
var bdata = b._data;
// result
var c = 0;
// loop data
for (var i = 0; i < n; i++) {
// multiply and accumulate
c = add(c, multiply(adata[i], bdata[i]));
}
return c;
};
/**
* C = A * B
*
* @param {Matrix} a Dense Vector (M)
* @param {Matrix} b Matrix (MxN)
*
* @return {Matrix} Dense Vector (N)
*/
var _multiplyVectorMatrix = function (a, b) {
// process storage
switch (b.storage()) {
case 'dense':
return _multiplyVectorDenseMatrix(a, b);
}
throw new Error('Not implemented');
};
/**
* C = A * B
*
* @param {Matrix} a Dense Vector (M)
* @param {Matrix} b Dense Matrix (MxN)
*
* @return {Matrix} Dense Vector (N)
*/
var _multiplyVectorDenseMatrix = function (a, b) {
// a dense
var adata = a._data;
var asize = a._size;
// b dense
var bdata = b._data;
var bsize = b._size;
// rows & columns
var alength = asize[0];
var bcolumns = bsize[1];
// result
var c = new Array(bcolumns);
// loop matrix columns
for (var j = 0; j < bcolumns; j++) {
// sum
var sum = 0;
// loop vector
for (var i = 0; i < alength; i++) {
// multiply & accumulate
sum = add(sum, multiply(adata[i], bdata[i][j]));
}
c[j] = sum;
}
// check we need to squeeze the result into a scalar
if (bcolumns === 1)
return c[0];
// return matrix
return new DenseMatrix({
data: c,
size: [bcolumns]
});
};
/**
* C = A * B
*
* @param {Matrix} a Matrix (MxN)
* @param {Matrix} b Dense Vector (N)
*
* @return {Matrix} Dense Vector (M)
*/
var _multiplyMatrixVector = function (a, b) {
// process storage
switch (a.storage()) {
case 'dense':
return _multiplyDenseMatrixVector(a, b);
case 'sparse':
return _multiplySparseMatrixVector(a, b);
}
};
/**
* C = A * B
*
* @param {Matrix} a Matrix (MxN)
* @param {Matrix} b Matrix (NxC)
*
* @return {Matrix} Matrix (MxC)
*/
var _multiplyMatrixMatrix = function (a, b) {
// process storage
switch (a.storage()) {
case 'dense':
// process storage
switch (b.storage()) {
case 'dense':
return _multiplyDenseMatrixDenseMatrix(a, b);
case 'sparse':
return _multiplyDenseMatrixSparseMatrix(a, b);
}
break;
case 'sparse':
// process storage
switch (b.storage()) {
case 'dense':
return _multiplySparseMatrixDenseMatrix(a, b);
case 'sparse':
return _multiplySparseMatrixSparseMatrix(a, b);
}
break;
}
};
/**
* C = A * B
*
* @param {Matrix} a DenseMatrix (MxN)
* @param {Matrix} b Dense Vector (N)
*
* @return {Matrix} Dense Vector (M)
*/
var _multiplyDenseMatrixVector = function (a, b) {
// a dense
var adata = a._data;
var asize = a._size;
// b dense
var bdata = b._data;
// rows & columns
var arows = asize[0];
var acolumns = asize[1];
// result
var c = new Array(arows);
// loop matrix a rows
for (var i = 0; i < arows; i++) {
// current row
var row = adata[i];
// sum
var sum = 0;
// loop matrix a columns
for (var j = 0; j < acolumns; j++) {
// multiply & accumulate
sum = add(sum, multiply(row[j], bdata[j]));
}
c[i] = sum;
}
// check we need to squeeze the result into a scalar
if (arows === 1)
return c[0];
// return matrix
return new DenseMatrix({
data: c,
size: [arows]
});
};
/**
* C = A * B
*
* @param {Matrix} a DenseMatrix (MxN)
* @param {Matrix} b DenseMatrix (NxC)
*
* @return {Matrix} DenseMatrix (MxC)
*/
var _multiplyDenseMatrixDenseMatrix = function (a, b) {
// a dense
var adata = a._data;
var asize = a._size;
// b dense
var bdata = b._data;
var bsize = b._size;
// rows & columns
var arows = asize[0];
var acolumns = asize[1];
var bcolumns = bsize[1];
// result
var c = new Array(arows);
// loop matrix a rows
for (var i = 0; i < arows; i++) {
// current row
var row = adata[i];
// initialize row array
c[i] = new Array(bcolumns);
// loop matrix b columns
for (var j = 0; j < bcolumns; j++) {
// sum
var sum = 0;
// loop matrix a columns
for (var x = 0; x < acolumns; x++) {
// multiply & accumulate
sum = add(sum, multiply(row[x], bdata[x][j]));
}
c[i][j] = sum;
}
}
// check we need to squeeze the result into a scalar
if (arows === 1 && bcolumns === 1)
return c[0][0];
// return matrix
return new DenseMatrix({
data: c,
size: [arows, bcolumns]
});
};
/**
* C = A * B
*
* @param {Matrix} a DenseMatrix (MxN)
* @param {Matrix} b SparseMatrix (NxC)
*
* @return {Matrix} DenseMatrix (MxC)
*/
var _multiplyDenseMatrixSparseMatrix = function (a, b) {
// a dense
var adata = a._data;
var asize = a._size;
// b sparse
var bvalues = b._values;
var bindex = b._index;
var bptr = b._ptr;
var bsize = b._size;
// rows & columns
var arows = asize[0];
var bcolumns = bsize[1];
// result
var c = new Array(arows);
// loop a rows
for (var i = 0; i < arows; i++) {
// initialize row
c[i] = new Array(bcolumns);
// current row
var row = adata[i];
// loop b columns
for (var j = 0; j < bcolumns; j++) {
// sum
var sum = 0;
// values & index in column j
for (var k0 = bptr[j], k1 = bptr[j + 1], k = k0; k < k1; k++) {
// row
var x = bindex[k];
// multiply & accumulate
sum = add(sum, multiply(row[x], bvalues[k]));
}
c[i][j] = sum;
}
}
// check we need to squeeze the result into a scalar
if (arows === 1 && bcolumns === 1)
return c[0][0];
// return matrix
return new DenseMatrix({
data: c,
size: [arows, bcolumns]
});
};
/**
* C = A * B
*
* @param {Matrix} a SparseMatrix (MxN)
* @param {Matrix} b Dense Vector (N)
*
* @return {Matrix} SparseMatrix (M, 1)
*/
var _multiplySparseMatrixVector = function (a, b) {
// a sparse
var avalues = a._values;
var aindex = a._index;
var aptr = a._ptr;
// b dense
var bdata = b._data;
// rows & columns
var arows = a._size[0];
var brows = b._size[0];
// result
var cvalues = [];
var cindex = [];
var cptr = [];
// create sparse accumulator
var spa = new Spa(arows);
// update ptr
cptr.push(0);
// rows in b
for (var ib = 0; ib < brows; ib++) {
// b[ib]
var vbi = bdata[ib];
// check b[ib] != 0, avoid loops
if (!equal(vbi, 0)) {
// A values & index in ib column
for (var ka0 = aptr[ib], ka1 = aptr[ib + 1], ka = ka0; ka < ka1; ka++) {
// a row
var ia = aindex[ka];
// accumulate
spa.accumulate(ia, multiply(vbi, avalues[ka]));
}
}
}
// process spa
spa.forEach(0, arows - 1, function (x, v) {
cindex.push(x);
cvalues.push(v);
});
// update ptr
cptr.push(cvalues.length);
// check we need to squeeze the result into a scalar
if (arows === 1)
return cvalues.length === 1 ? cvalues[0] : 0;
// return sparse matrix
return new SparseMatrix({
values : cvalues,
index: cindex,
ptr: cptr,
size: [arows, 1]
});
};
/**
* C = A * B
*
* @param {Matrix} a SparseMatrix (MxN)
* @param {Matrix} b DenseMatrix (NxC)
*
* @return {Matrix} SparseMatrix (MxC)
*/
var _multiplySparseMatrixDenseMatrix = function (a, b) {
// a sparse
var avalues = a._values;
var aindex = a._index;
var aptr = a._ptr;
// b dense
var bdata = b._data;
// rows & columns
var arows = a._size[0];
var brows = b._size[0];
var bcolumns = b._size[1];
// result
var cvalues = [];
var cindex = [];
var cptr = [];
// process column
var processColumn = function (j, v) {
cindex.push(j);
cvalues.push(v);
};
// loop b columns
for (var jb = 0; jb < bcolumns; jb++) {
// update ptr
cptr.push(cvalues.length);
// create sparse accumulator
var spa = new Spa(arows);
// rows in jb
for (var ib = 0; ib < brows; ib++) {
// b[ib, jb]
var vbij = bdata[ib][jb];
// check b[ib, jb] != 0, avoid loops
if (!equal(vbij, 0)) {
// A values & index in ib column
for (var ka0 = aptr[ib], ka1 = aptr[ib + 1], ka = ka0; ka < ka1; ka++) {
// a row
var ia = aindex[ka];
// accumulate
spa.accumulate(ia, multiply(vbij, avalues[ka]));
}
}
}
// process sparse accumulator
spa.forEach(0, arows - 1, processColumn);
}
// update ptr
cptr.push(cvalues.length);
// check we need to squeeze the result into a scalar
if (arows === 1 && bcolumns === 1)
return cvalues.length === 1 ? cvalues[0] : 0;
// return sparse matrix
return new SparseMatrix({
values : cvalues,
index: cindex,
ptr: cptr,
size: [arows, bcolumns]
});
};
/**
* C = A * B
*
* @param {Matrix} a SparseMatrix (MxN)
* @param {Matrix} b SparseMatrix (NxC)
*
* @return {Matrix} SparseMatrix (MxC)
*/
var _multiplySparseMatrixSparseMatrix = function (a, b) {
// a sparse
var avalues = a._values;
var aindex = a._index;
var aptr = a._ptr;
// b sparse
var bvalues = b._values;
var bindex = b._index;
var bptr = b._ptr;
// rows & columns
var arows = a._size[0];
var bcolumns = b._size[1];
// result
var cvalues = [];
var cindex = [];
var cptr = [];
// process column in C
var processColumn = function (i, v) {
cindex.push(i);
cvalues.push(v);
};
// loop b columns
for (var jb = 0; jb < bcolumns; jb++) {
// update ptr
cptr.push(cvalues.length);
// create sparse accumulator
var spa = new Spa(arows);
// B values & index in j
for (var kb0 = bptr[jb], kb1 = bptr[jb + 1], kb = kb0; kb < kb1; kb++) {
// b row
var ib = bindex[kb];
// A values & index in ib column
for (var ka0 = aptr[ib], ka1 = aptr[ib + 1], ka = ka0; ka < ka1; ka++) {
// a row
var ia = aindex[ka];
// accumulate
spa.accumulate(ia, multiply(bvalues[kb], avalues[ka]));
}
}
// process sparse accumulator
spa.forEach(0, arows - 1, processColumn);
}
// update ptr
cptr.push(cvalues.length);
// check we need to squeeze the result into a scalar
if (arows === 1 && bcolumns === 1)
return cvalues.length === 1 ? cvalues[0] : 0;
// return sparse matrix
return new SparseMatrix({
values : cvalues,
index: cindex,
ptr: cptr,
size: [arows, bcolumns]
});
};
return multiply;
}
exports.name = 'multiply';
exports.factory = factory;