On entry: the dimension of the array
work as declared in the (sub)program from which
f08kcf is called.
The exact minimum amount of workspace needed depends on
m,
n and
nrhs. As long as
lwork is at least
where
is equal to the maximum size of the subproblems at the bottom of the computation tree (usually about
),
and
, the code will execute correctly.
If
, a workspace query is assumed; the routine only calculates the optimal size of the
work array and the minimum size of the
iwork array, and returns these values as the first entries of the
work and
iwork arrays, and no error message related to
lwork is issued.
Suggested value:
for optimal performance,
lwork should generally be larger than the minimum required as set out above. Consider increasing
lwork by at least
, where
is the optimal
block size.