void pivoted_gauss_jordan_elimination(const DenseMatrix &A, DenseMatrix &B,
std::vector<unsigned> &pivotlist)
{
CSYMPY_ASSERT(A.row_ == B.row_ && A.col_ == B.col_);
CSYMPY_ASSERT(pivotlist.size() == A.row_);
unsigned row = A.row_, col = A.col_;
unsigned index = 0, i, j, k;
RCP<const Basic> scale;
B.m_ = A.m_;
for (i = 0; i < row; i++)
pivotlist[i] = i;
for (i = 0; i < col; i++) {
if (index == row)
break;
k = pivot(B, index, i);
if (k == row)
continue;
if (k != index) {
row_exchange_dense(B, k, index);
std::swap(pivotlist[k], pivotlist[index]);
}
scale = div(one, B.m_[index*col + i]);
row_mul_scalar_dense(B, index, scale);
for (j = 0; j < row; j++) {
if (j == index)
continue;
scale = mul(minus_one, B.m_[j*col + i]);
row_add_row_dense(B, j, index, scale);
}
index++;
}
}
void pivoted_gauss_jordan_elimination(const DenseMatrix &A, DenseMatrix &B,
permutelist &pl)
{
SYMENGINE_ASSERT(A.row_ == B.row_ and A.col_ == B.col_);
unsigned row = A.row_, col = A.col_;
unsigned index = 0, i, j, k;
RCP<const Basic> scale;
B.m_ = A.m_;
for (i = 0; i < col; i++) {
if (index == row)
break;
k = pivot(B, index, i);
if (k == row)
continue;
if (k != index) {
row_exchange_dense(B, k, index);
pl.push_back({k, index});
}
scale = div(one, B.m_[index * col + i]);
row_mul_scalar_dense(B, index, scale);
for (j = 0; j < row; j++) {
if (j == index)
continue;
scale = mul(minus_one, B.m_[j * col + i]);
row_add_row_dense(B, j, index, scale);
}
index++;
}
}
