void Householder<T>::mulLeft(NDArray<T>& matrix, const NDArray<T>& tail, const T coeff) {
// if(matrix.rankOf() != 2)
// throw "ops::helpers::Householder::mulLeft method: input array must be 2D matrix !";
if(matrix.sizeAt(0) == 1)
matrix *= (T)1. - coeff;
else if(coeff != (T)0.) {
NDArray<T>* bottomPart = matrix.subarray({{1, matrix.sizeAt(0)}, {}});
NDArray<T> bottomPartCopy = *bottomPart;
if(tail.isColumnVector()) {
NDArray<T> column = tail;
NDArray<T>* row = tail.transpose();
NDArray<T> resultingRow = mmul(*row, bottomPartCopy);
NDArray<T>* fistRow = matrix.subarray({{0,1}, {}});
resultingRow += *fistRow;
*fistRow -= resultingRow * coeff;
*bottomPart -= mmul(column, resultingRow) * coeff;
delete row;
delete fistRow;
}
else {
NDArray<T> row = tail;
NDArray<T>* column = tail.transpose();
NDArray<T> resultingRow = mmul(row, bottomPartCopy);
NDArray<T>* fistRow = matrix.subarray({{0,1}, {}});
resultingRow += *fistRow;
*fistRow -= resultingRow * coeff;
*bottomPart -= mmul(*column, resultingRow) * coeff;
delete column;
delete fistRow;
}
delete bottomPart;
}
}
void Householder<T>::mulRight(NDArray<T>& matrix, const NDArray<T>& tail, const T coeff) {
// if(matrix.rankOf() != 2)
// throw "ops::helpers::Householder::mulRight method: input array must be 2D matrix !";
if(matrix.sizeAt(1) == 1)
matrix *= (T)1. - coeff;
else if(coeff != (T)0.) {
NDArray<T>* rightPart = matrix.subarray({{}, {1, matrix.sizeAt(1)}});
NDArray<T> rightPartCopy = *rightPart;
NDArray<T>* fistCol = matrix.subarray({{},{0,1}});
if(tail.isColumnVector()) {
NDArray<T> column = tail;
NDArray<T>* row = tail.transpose();
NDArray<T> resultingCol = mmul(rightPartCopy, column);
resultingCol += *fistCol;
*fistCol -= resultingCol * coeff;
*rightPart -= mmul(resultingCol, *row) * coeff;
delete row;
}
else {
NDArray<T> row = tail;
NDArray<T>* column = tail.transpose();
NDArray<T> resultingCol = mmul(rightPartCopy, *column);
resultingCol += *fistCol;
*fistCol -= resultingCol * coeff;
*rightPart -= mmul(resultingCol, row) * coeff;
delete column;
}
delete rightPart;
delete fistCol;
}
}
