void THLapack_(gels)(char trans, int m, int n, int nrhs, real *a, int lda, real *b, int ldb, real *work, int lwork, int *info)
{
#ifdef USE_LAPACK
#if defined(TH_REAL_IS_DOUBLE)
dgels_(&trans, &m, &n, &nrhs, a, &lda, b, &ldb, work, &lwork, info);
#else
sgels_(&trans, &m, &n, &nrhs, a, &lda, b, &ldb, work, &lwork, info);
#endif
#else
THError("gels : Lapack library not found in compile time\n");
#endif
}
static int fmat_solve_ls_t_inplace(int mi, int ni, float *a, float *bx) {
/* solve system */
FINTEGER info;
FINTEGER m=mi, nrhs=1, lda=mi, lwork=-1;
FINTEGER n=ni, ldb=n;
float work_sz;
sgels_("Transposed", &m, &n, &nrhs, a, &lda,
bx, &ldb, &work_sz, &lwork, &info);
lwork = (long)work_sz;
float *work = fvec_new(lwork);
sgels_("Transposed", &m, &n, &nrhs, a, &lda,
bx, &n, work, &lwork, &info);
free(work);
return info;
}
void THLapack_(gels)(char trans, int m, int n, int nrhs, real *a, int lda, real *b, int ldb, real *work, int lwork, int *info)
{
#ifdef USE_LAPACK
#if defined(TH_REAL_IS_DOUBLE)
extern void dgels_(char *trans, int *m, int *n, int *nrhs, double *a, int *lda, double *b, int *ldb, double *work, int *lwork, int *info);
dgels_(&trans, &m, &n, &nrhs, a, &lda, b, &ldb, work, &lwork, info);
#else
extern void sgels_(char *trans, int *m, int *n, int *nrhs, float *a, int *lda, float *b, int *ldb, float *work, int *lwork, int *info);
sgels_(&trans, &m, &n, &nrhs, a, &lda, b, &ldb, work, &lwork, info);
#endif
#else
THError("gels : Lapack library not found in compile time\n");
#endif
}
DLLEXPORT MKL_INT s_thin_qr_solve(MKL_INT m, MKL_INT n, MKL_INT bn, float a[], float b[], float x[], float work[], MKL_INT len)
{
MKL_INT info = 0;
float* clone_a = new float[m*n];
std::memcpy(clone_a, a, m*n*sizeof(float));
float* clone_b = new float[m*bn];
std::memcpy(clone_b, b, m*bn*sizeof(float));
char N = 'N';
sgels_(&N, &m, &n, &bn, clone_a, &m, clone_b, &m, work, &len, &info);
for (MKL_INT i = 0; i < n; ++i)
{
for (MKL_INT j = 0; j < bn; ++j)
{
x[j * n + i] = clone_b[j * m + i];
}
}
delete[] clone_a;
delete[] clone_b;
return info;
}
