Re: Who uses clapack?

From: Ron Shepard (ron-shepard_at_NOSPAM.comcast.net)
Date: 12/12/04 

Date: Sun, 12 Dec 2004 11:21:35 -0600

In article <slrncroaij.tik.romanNOSPAM@theta1.cft.edu.pl>,
 Roman Werpachowski <"r o m a nNOSPAM"@theta1.cft.edu.pl> wrote:

> The only sensible way would be to have two functions: one which does the
> allocation, another which does not. The problem is, that sometimes one
> can flexibly choose a work space area, like in (D,S)SYEV routine. Small
> workspace conserves memory but large workspace gives better convergence.
> Which options should the self-allocating version of (D,S)SYEV choose?

Modern Fortran allows optional arguments, so the "sensible" way in
that language would be to specify the workspace with an optional
array. If specified during the call, then it is used, otherwise the
subroutine allocates its own workspace. Of course, this puts
additional burdens on other languages in cross-language projects to
support the fortran calling conventions. BTW, fortran also allows
the call to use a generic name (e.g. call syev() in the above
example), which is resolved to the specific precision based on the
data types of its arguments, in order to eliminate the (D,S)
portability problems when moving code between machines.

$.02 -Ron Shepard

Relevant Pages

  • Re: Who uses clapack?
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