#include<iostream>
#include<gsl/gsl_matrix.h>
#include<gsl/gsl_vector.h>
#include<gsl/gsl_eigen.h>



using namespace std;



int main(int argc, char *argv[]){

  size_t length = 45;

	gsl_vector * evalues = gsl_vector_calloc(length);
	gsl_matrix * evectors = gsl_matrix_calloc(length, length);
  gsl_eigen_symmv_workspace * w = gsl_eigen_symmv_alloc(length);
	gsl_matrix * m = gsl_matrix_alloc(length, length);
	gsl_vector * v = gsl_vector_calloc(length);

	FILE *f=fopen("/home/wolff/testmatrix.dat","r");
	gsl_matrix_fscanf(f,m);
	fclose(f);

  for(size_t i = 0; i < length; i++){
    for(size_t j = 0; j < length; j++){
      cout << gsl_matrix_get(m,i,j) << " ";
      //if(i==j){
      //  gsl_matrix_set(m,i,j,1.);
      //}
    }
    cout << endl;
  }

  cout << "compute eigensystem" << endl;
	gsl_eigen_symmv(m, evalues, evectors, w);
  cout << "computed eigensystem" << endl;
	gsl_eigen_symmv_sort(evalues, evectors, GSL_EIGEN_SORT_VAL_DESC);
	gsl_matrix_get_col(v, evectors, 0);

  for(size_t i = 0; i < length; i++){
    cout << gsl_vector_get(v,i) << endl;
	}

 
  for(size_t i = 0; i < length; i++){ 
    cout << "eigenvalues" << gsl_vector_get(evalues,i) << endl;
	}


}