Sherman-Morrison/SM-MaponiA3.cpp

103 lines
2.8 KiB
C++

// SM-MaponiA3.cpp
#include "SM-MaponiA3.hpp"
void Sherman_Morrison(int **Slater0, double **Slater_inv, unsigned int *Dim, unsigned int *N_updates, int **Updates, unsigned int *Updates_index) {
unsigned int k, l, lbar, i, j, tmp, M = *Dim;
unsigned int *p = new unsigned int[M+1];
double *breakdown = new double[M+1];
double alpha, beta;
for (i = 0; i < M+1; i++) {
p[i] = i;
}
int **Id = new int*[M];
for (i = 0; i < M; i++) Id[i] = new int[M];
for (i = 0; i < M; i++) {
for (j = 0; j < M; j++) {
if (i != j) Id[i][j] = 0;
else Id[i][j] = 1;
}
}
// Declare auxiliary solution matrix ylk
double ***ylk = new double**[M];
for (l = 0; l < M; l++) {
ylk[l] = new double*[M+1];
for (k = 0; k < M+1; k++) {
ylk[l][k] = new double[M+1];
}
}
// Initialize ylk with zeros
for (l = 0; l < M; l++) {
for (k = 0; k < M+1; k++) {
for (i = 0; i < M+1; i++) {
ylk[l][k][i] = 0;
}
}
}
// Calculate all the y0k in M^2 multiplications instead of M^3
for (k = 1; k < M+1; k++) {
for (i = 1; i < M+1; i++) {
ylk[0][k][i] = Slater_inv[i-1][i-1] * Updates[i-1][k-1];
}
}
// Calculate all the ylk from the y0k
for (l = 1; l < M; l++) {
for (j = l; j < M+1; j++) {
breakdown[j] = abs( 1 + ylk[l-1][p[j]][p[j]] );
}
lbar = getMaxIndex(breakdown, M+1);
for (i = 0; i < M; i++) {
breakdown[i] = 0;
}
tmp = p[l];
p[l] = p[lbar];
p[lbar] = tmp;
for (k = l+1; k < M+1; k++) {
beta = 1 + ylk[l-1][p[l]][p[l]];
if (beta == 0) {
cout << "Break-down condition occured. Exiting..." << endl;
exit;
}
for (i = 1; i < M+1; i++) {
alpha = ylk[l-1][p[k]][p[l]] / beta;
ylk[l][p[k]][i] = ylk[l-1][p[k]][i] - alpha * ylk[l-1][p[l]][i];
}
}
}
// Construct A-inverse from A0-inverse and the ylk
double **U;
double **Al = new double*[M];
for (i = 0; i < M; i++) Al[i] = new double[M];
for (l = 0; l < M; l++) {
k = l+1;
U = outProd(ylk[l][p[k]], Id[p[k]-1], M);
beta = 1 + ylk[l][p[k]][p[k]];
for (i = 0; i < M; i++) {
for (j = 0; j < M; j++) {
Al[i][j] = Id[i][j] - U[i][j] / beta;
}
}
Slater_inv = matMul(Al, Slater_inv, M);
}
delete [] p, breakdown;
for (i = 0; i < M; i++) {
delete [] Id[i];
delete [] U[i];
delete [] Al[i];
}
for (l = 0; l < M; l++) {
for (k = 0; k < M+1; k++) {
delete [] ylk[l][k];
}
delete [] ylk[l];
}
}