void Matrix::rref() {
int l = 0;
int r = 0;
int i = 0;
double v = 0.0;
for (r = 0; r < nRows; r++) {
if (nCols <= l) {
break;
}
i = r;
while (get(i + 1, l + 1) == 0.0) {
i++;
if (nRows == i) {
i = r;
l++;
if (nCols == l) {
break;
}
}
}
rowSwap(i + 1, r + 1);
v = get(r + 1, l + 1);
if (v != 0.0) {
rowMul(r + 1, 1 / v);
}
for (i = 0; i < nRows; i++) {
if (i != r) {
v = get(i + 1, l + 1);
rowAddMul(i + 1, r + 1, 0 - v);
}
}
l++;
}
}
void setMatrix(double **A, int n, int m){
int i, j;
for(i = 0;i<n-1;i++){
for(j=i+1;j<n;j++){
if(*(*(A+i)) < *(*(A+j))){
rowSwap(A, i, j, n, m);
}
}
}
}
vector<T> gaussElim<T>::operator()(matrix<T>& A, vector<T>& b)
{
vector<T> x(b);
int p = 1;
T scalar;
T* s = new T[A.getRows()];
for(int i = 0; i < A.getRows(); i++)
{
s[i] = 0;
for(int j = 0; j < A.getCols(); j++)
{
if(s[i] < abs(A(i+1,j+1)))
{
s[i] = abs(A(i+1, j+1));
}
}
}
for(int i = 1; i <= A.getCols(); i++)
{
p = i;
for(int k = i + 1; k <= A.getCols(); k++)
{
if(abs(A(p, i))/s[p-1] < abs(A(k, i))/s[k-1])
{
p = k;
}
}
if(p != i)
{
rowSwap(i, p, A, b);
}
for(int k = i + 1; k <= A.getCols(); k++)
{
scalar = -A(k,i)/A(i,i);
rowAdd(k, i, scalar, A, b);
A(k,i) = 0;
}
}
for(int i = A.getCols(); i > 0; i--)
{
scalar = 0;
for(int j = i; j < A.getCols(); j++)
{
scalar = scalar + x[j] * A(i,j+1);
}
if(A(i, i) != 0)
{
x[i - 1] = (b[i - 1] - scalar)/A(i,i);
}
}
delete [] s;
return x;
}
void matrixRREF(Matrix m) {
int prealloc = alloc_matrix;
int pivotCol = 0;
int pivotRow = 0;
int row;
FTYPE absVal;
int tmp = 0;
while(1) {
/* Select the row with the largest absolute value, or move to the next row
if there is no value int the column */
absVal = 0.0;
while( absVal == 0.0 && pivotCol < m->col_dim) {
absVal = ABS(ME(m,pivotRow,pivotCol));
tmp = pivotRow;
for(row = pivotRow+1; row < m->row_dim; row++) {
if( ABS(ME(m,row,pivotCol)) > absVal ) {
absVal = ABS(ME(m,row,pivotCol));
tmp = row;
}
}
if(absVal == 0) {
pivotCol++;
}
}
/* return if the RREF has been found */
if( pivotCol >= m->col_dim || pivotRow >= m->row_dim) return;
/* make sure that the pivot row is in the correct position */
if(pivotRow != tmp) rowSwap(m,tmp,pivotRow);
/* rescale the Pivot Row */
rowMult( m, pivotRow,1.0/ME(m,pivotRow,pivotCol) );
/* This part of the algorithm is not as effecent as it could be,
but it works for now. */
for(row = 0; row < m->row_dim; row++) {
if(row != pivotRow) {
rowMultAdd(m,pivotRow,row,-ME(m,row,pivotCol));
}
}
pivotRow++;
pivotCol++;
}
if(prealloc != alloc_matrix) {
printf("Error deallocating matricies <%s>: pre=%d post=%d",__FUNCTION__, prealloc, alloc_matrix);
exit(1);
}
}
