The LLS test program tests the PxGELS driver routine for computing solutions
to over- and underdetermined, full-rank systems of
linear equations (
is
-by-
). For each test
matrix type, we generate three matrices: One which is scaled near
underflow, a matrix with moderate norm, and one which is scaled
near overflow.
The PxGELS driver
computes the least-squares
solutions (when ) and the
minimum-norm solution (when
) for an
-by-
matrix
of full rank. To test PxGELS, we generate a diagonally
dominant matrix
, and for
and
, we