/** * Compute the sum of this matrix and {@code m}. * * @param m Matrix to be added. * @return {@code this} + {@code m}. * @throws MatrixDimensionMismatchException if {@code m} is not the same * size as {@code this}. */ public OpenMapRealMatrix add(OpenMapRealMatrix m) { //MatrixUtils.checkAdditionCompatible(this, m); OpenMapRealMatrix @out = new OpenMapRealMatrix(this); for (OpenIntToDoubleHashMap.Iterator iterator = m.entries.iterator(); iterator.hasNext();) { iterator.advance(); int row = iterator.key() / columns; int col = iterator.key() - row * columns; @out.setEntry(row, col, getEntry(row, col) + iterator.value()); } return(@out); }
/** * Postmultiply this matrix by {@code m}. * * @param m Matrix to postmultiply by. * @return {@code this} * {@code m}. * @throws DimensionMismatchException if the number of rows of {@code m} * differ from the number of columns of {@code this} matrix. * @throws NumberIsTooLargeException if the total number of entries of the * product is larger than {@code Integer.MAX_VALUE}. */ public OpenMapRealMatrix multiply(OpenMapRealMatrix m) { // Safety check. //MatrixUtils.checkMultiplicationCompatible(this, m); int outCols = m.getColumnDimension(); OpenMapRealMatrix @out = new OpenMapRealMatrix(rows, outCols); for (OpenIntToDoubleHashMap.Iterator iterator = entries.iterator(); iterator.hasNext();) { iterator.advance(); double value = iterator.value(); int key = iterator.key(); int i = key / columns; int k = key % columns; for (int j = 0; j < outCols; ++j) { int rightKey = m.computeKey(k, j); if (m.entries.containsKey(rightKey)) { int outKey = @out.computeKey(i, j); double outValue = @out.entries.get(outKey) + value * m.entries.get(rightKey); if (outValue == 0.0) { @out.entries.remove(outKey); } else { @out.entries.put(outKey, outValue); } } } } return(@out); }
/** * Compute the outer product. * * @param v Vector with which outer product should be computed. * @return the matrix outer product between this instance and {@code v}. */ public virtual RealMatrix outerProduct(RealVector v) { //throw new NotImplementedException(); int m = getDimension(); int n = v.getDimension(); RealMatrix product; if (v is SparseRealVector || this is SparseRealVector) { product = new OpenMapRealMatrix(m, n); } else { product = new Array2DRowRealMatrix(m, n); } for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { product.setEntry(i, j, getEntry(i) * v.getEntry(j)); } } return(product); }
/** * Build a matrix by copying another one. * * @param matrix matrix to copy. */ public OpenMapRealMatrix(OpenMapRealMatrix matrix) { rows = matrix.rows; columns = matrix.columns; entries = new OpenIntToDoubleHashMap(matrix.entries); }