QMat RMat::QMat::makeDefPos()
{
QVec vals ( rows,0. );
QMat V = eigenValsVectors ( vals );
//V.print("autovectores originales");
for ( int i=0; i< rows; i++ )
{
if ( vals ( i ) <= 0. )
vals ( i ) = 0.0000001;
}
QMat DD = QMat::makeDiagonal ( vals );
QMat R = ( V * ( DD * V.transpose() ) );
return R;
}
QMat QMat::invert( ) const
{
Q_ASSERT( isSquare() );
QMat R ( rows, cols );
#ifdef COMPILE_IPP
T pBuffer[cols*cols+cols];
IppStatus status = ippmInvert_m_32f ( getReadData(), cols*sizeof ( T ), sizeof ( T ), pBuffer, R.toData(), cols*sizeof ( T ), sizeof ( T ), cols );
#else
int status =1;
if(determinant()!=0)
{
status=0;
gsl_matrix *u = *this;
gsl_vector *s = gsl_vector_alloc (cols);
gsl_matrix *v = gsl_matrix_alloc (cols,cols);
gsl_vector *work = gsl_vector_alloc (cols);
gsl_matrix *X = gsl_matrix_alloc (cols,cols);
gsl_linalg_SV_decomp_mod(u, X, v, s, work);
gsl_matrix_free(X);
// pasamos de vuelta:
QMat U = u;
QMat V = v;
gsl_matrix_free(u);
gsl_matrix_free(v);
gsl_vector_free(work);
QMat S = QMat::zeros(rows,cols);
for (int i = 0; i < cols; i++)
S(i,i) = 1 / gsl_vector_get(s, i);
gsl_vector_free(s);
return V * S * U.transpose();
}
#endif
if ( status == 0 )
return R;
else
{
QString ex= "QMat::invert() - Singular matrix";
throw ex;
}
}
