Files
igl/examples/svd/example.cpp
T

97 lines
1.8 KiB
C++
Executable File

#include <igl/svd.h>
#include <cstdlib>
#include <Accelerate/Accelerate.h>
#include <cstdio>
/* Auxiliary routines prototypes */
extern void print_matrix( char* desc, int m, int n, double* a, int lda );
/* Parameters */
void print3x3(const char * s, double * a)
{
printf("%s =\n",s);
for(int i = 0;i<3;i++)
{
for(int j = 0;j<3;j++)
{
printf("%g ",a[j*3+i]);
}
printf("\n");
}
printf("\n");
}
int main(int argc, char * argv[])
{
//// List of rest positions
//// (0,1)
//// / \
//// / \
//// / \
//// / \
//// (-1,0)-----(1,0)
////
//double rest[3][3] = {
// {-1,0,0},
// {1,0,0},
// {0,1,0}};
//// List of pose positions
////
//// (0,1)
//// | \
//// | \
//// | (1,0)
//// | /
//// | /
//// (0,-1)
//double pose[3][3] = {
// {0,1,0},
// {0,-1,0},
// {1,0,0}};
//// Compute covariance matrix C
//double C[3*3];
//// Initialize to zero
//for(int i = 0;i<3*3;i++)
//{
// C[i] = 0;
//}
//// Loop over vertices
//for(int i = 0;i<3;i++)
//{
// // Compute outer product rest[i] * pose[i]
// // Loop over coordinates
// for(int j = 0;j<3;j++)
// {
// // Loop over coordinates
// for(int k = 0;k<3;k++)
// {
// C[k*3+j] = rest[i][j] * pose[i][k];
// }
// }
//}
//print3x3("C",C);
//
//double C[3*3] = {8,3,4,1,5,9,6,7,2};
double C[3*3] = {5242.55,3364,-0,-8170.15,-5242.56,0,-0,-0,0};
double u[3*3],s[3],vt[3*3];
print3x3("C",C);
// Compute SVD of C
igl::svd3x3(C,u,s,vt);
print3x3("u",u);
print3x3("vt",vt);
// Compute R = u*vt
double R[3*3];
const double _3 = 3;
const double _1 = 1;
cblas_dgemm(CblasColMajor, CblasNoTrans,CblasNoTrans,3,3,3,1,u,3,vt,3,1,R,3);
print3x3("RT (transposed to be row-major)",R);
return 0;
}