177 lines
4.4 KiB
JavaScript
177 lines
4.4 KiB
JavaScript
import { factory } from '../../utils/factory.js';
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import { isMatrix } from '../../utils/is.js';
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var name = 'dot';
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var dependencies = ['typed', 'addScalar', 'multiplyScalar', 'conj', 'size'];
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export var createDot = /* #__PURE__ */factory(name, dependencies, _ref => {
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var {
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typed,
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addScalar,
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multiplyScalar,
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conj,
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size
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} = _ref;
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/**
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* Calculate the dot product of two vectors. The dot product of
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* `A = [a1, a2, ..., an]` and `B = [b1, b2, ..., bn]` is defined as:
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*
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* dot(A, B) = conj(a1) * b1 + conj(a2) * b2 + ... + conj(an) * bn
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*
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* Syntax:
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*
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* math.dot(x, y)
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*
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* Examples:
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*
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* math.dot([2, 4, 1], [2, 2, 3]) // returns number 15
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* math.multiply([2, 4, 1], [2, 2, 3]) // returns number 15
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*
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* See also:
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*
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* multiply, cross
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*
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* @param {Array | Matrix} x First vector
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* @param {Array | Matrix} y Second vector
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* @return {number} Returns the dot product of `x` and `y`
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*/
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return typed(name, {
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'Array | DenseMatrix, Array | DenseMatrix': _denseDot,
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'SparseMatrix, SparseMatrix': _sparseDot
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});
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function _validateDim(x, y) {
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var xSize = _size(x);
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var ySize = _size(y);
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var xLen, yLen;
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if (xSize.length === 1) {
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xLen = xSize[0];
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} else if (xSize.length === 2 && xSize[1] === 1) {
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xLen = xSize[0];
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} else {
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throw new RangeError('Expected a column vector, instead got a matrix of size (' + xSize.join(', ') + ')');
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}
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if (ySize.length === 1) {
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yLen = ySize[0];
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} else if (ySize.length === 2 && ySize[1] === 1) {
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yLen = ySize[0];
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} else {
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throw new RangeError('Expected a column vector, instead got a matrix of size (' + ySize.join(', ') + ')');
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}
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if (xLen !== yLen) throw new RangeError('Vectors must have equal length (' + xLen + ' != ' + yLen + ')');
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if (xLen === 0) throw new RangeError('Cannot calculate the dot product of empty vectors');
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return xLen;
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}
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function _denseDot(a, b) {
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var N = _validateDim(a, b);
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var adata = isMatrix(a) ? a._data : a;
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var adt = isMatrix(a) ? a._datatype : undefined;
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var bdata = isMatrix(b) ? b._data : b;
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var bdt = isMatrix(b) ? b._datatype : undefined; // are these 2-dimensional column vectors? (as opposed to 1-dimensional vectors)
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var aIsColumn = _size(a).length === 2;
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var bIsColumn = _size(b).length === 2;
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var add = addScalar;
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var mul = multiplyScalar; // process data types
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if (adt && bdt && adt === bdt && typeof adt === 'string') {
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var dt = adt; // find signatures that matches (dt, dt)
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add = typed.find(addScalar, [dt, dt]);
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mul = typed.find(multiplyScalar, [dt, dt]);
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} // both vectors 1-dimensional
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if (!aIsColumn && !bIsColumn) {
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var c = mul(conj(adata[0]), bdata[0]);
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for (var i = 1; i < N; i++) {
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c = add(c, mul(conj(adata[i]), bdata[i]));
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}
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return c;
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} // a is 1-dim, b is column
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if (!aIsColumn && bIsColumn) {
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var _c = mul(conj(adata[0]), bdata[0][0]);
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for (var _i = 1; _i < N; _i++) {
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_c = add(_c, mul(conj(adata[_i]), bdata[_i][0]));
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}
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return _c;
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} // a is column, b is 1-dim
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if (aIsColumn && !bIsColumn) {
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var _c2 = mul(conj(adata[0][0]), bdata[0]);
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for (var _i2 = 1; _i2 < N; _i2++) {
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_c2 = add(_c2, mul(conj(adata[_i2][0]), bdata[_i2]));
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}
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return _c2;
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} // both vectors are column
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if (aIsColumn && bIsColumn) {
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var _c3 = mul(conj(adata[0][0]), bdata[0][0]);
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for (var _i3 = 1; _i3 < N; _i3++) {
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_c3 = add(_c3, mul(conj(adata[_i3][0]), bdata[_i3][0]));
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}
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return _c3;
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}
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}
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function _sparseDot(x, y) {
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_validateDim(x, y);
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var xindex = x._index;
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var xvalues = x._values;
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var yindex = y._index;
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var yvalues = y._values; // TODO optimize add & mul using datatype
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var c = 0;
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var add = addScalar;
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var mul = multiplyScalar;
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var i = 0;
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var j = 0;
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while (i < xindex.length && j < yindex.length) {
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var I = xindex[i];
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var J = yindex[j];
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if (I < J) {
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i++;
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continue;
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}
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if (I > J) {
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j++;
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continue;
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}
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if (I === J) {
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c = add(c, mul(xvalues[i], yvalues[j]));
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i++;
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j++;
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}
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}
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return c;
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} // TODO remove this once #1771 is fixed
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function _size(x) {
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return isMatrix(x) ? x.size() : size(x);
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}
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}); |