I am trying to solve a linear least squares problem using LAPACK's specialized routines. Right after DGELS returns, the variables A and B are unchanged but info evaluates to 0. I am using PGI Fortran 7.2-5 with BLAS and LAPACK as released by PGI, on a Dell Precision T7400.
Has anyone else experienced this problem? Is there something I am not doing right? I even tried for a simple 2x2 matrix but the outcome was the same: A and B had the same value as before entering DGELS
- Code: Select all
call DGELS(tr, 2, 2, 1, amat, 2, bvec, 2, ym, -1, infols)
- Code: Select all
[alexgc@predeal SWE_NEW]$ ./sensobs
RHS before
1.000000000000000 1.000000000000000
1.000000000000000 -1.000000000000000
LHS before
1.000000000000000
0.000000000000000
info (as returned by DGELS) = 0
RHS after <=> factorization
1.000000000000000 1.000000000000000
1.000000000000000 -1.000000000000000
LHS after <=> solution
1.000000000000000
0.000000000000000
FORTRAN STOP