- matrix_mult(C,A,A);
- matrix_mult(A,C,G);
- }
- catch(exception& e) {
- m->errorOut(e, "PCACommand", "recenter");
- exit(1);
- }
-
-}
-
-/*********************************************************************************************************************************/
-
-// This function is taken from Numerical Recipes in C++ by Press et al., 2nd edition, pg. 479
-
-void PCACommand::tred2(vector<vector<double> >& a, vector<double>& d, vector<double>& e){
- try {
- double scale, hh, h, g, f;
-
- int n = a.size();
-
- d.resize(n);
- e.resize(n);
-
- for(int i=n-1;i>0;i--){
- int l=i-1;
- h = scale = 0.0000;
- if(l>0){
- for(int k=0;k<l+1;k++){
- scale += fabs(a[i][k]);
- }
- if(scale == 0.0){
- e[i] = a[i][l];
- }
- else{
- for(int k=0;k<l+1;k++){
- a[i][k] /= scale;
- h += a[i][k] * a[i][k];
- }
- f = a[i][l];
- g = (f >= 0.0 ? -sqrt(h) : sqrt(h));
- e[i] = scale * g;
- h -= f * g;
- a[i][l] = f - g;
- f = 0.0;
- for(int j=0;j<l+1;j++){
- a[j][i] = a[i][j] / h;
- g = 0.0;
- for(int k=0;k<j+1;k++){
- g += a[j][k] * a[i][k];
- }
- for(int k=j+1;k<l+1;k++){
- g += a[k][j] * a[i][k];
- }
- e[j] = g / h;
- f += e[j] * a[i][j];
- }
- hh = f / (h + h);
- for(int j=0;j<l+1;j++){
- f = a[i][j];
- e[j] = g = e[j] - hh * f;
- for(int k=0;k<j+1;k++){
- a[j][k] -= (f * e[k] + g * a[i][k]);
- }
- }
- }
- }
- else{
- e[i] = a[i][l];
- }