Response #1: 2005-08-09

General

1. Is dense linear algebra a performance bottleneck in your applications?
No

2. How often do your applications use the arithmetic precisions listed below:

3. What dense matrix sizes are most important or time-consuming for your application?
10,000s X 10,000s

4. Does your application come close to, or run out of memory on important problems?
Yes

5. Number of processors used for your application:

6. Which architectures do you use or intend to use in the next three years?
Sequential, Multi-core-thread, Distributed-memory

8. Please rank how the following features would be useful to your current or planned applications?

9. Do your applications solve linear algebra problems of the type?
General linear systems, Symmetric eigenvalue, Least-square problems, SVDs

LAPACK Usage

1. Do you use LAPACK (or a vendor version of LAPACK )?
Yes

4. If you use LAPACK, do you use a vendors version or one obtained directly from Netlib?
Netlib

6. Do your applications make direct LAPACK calls?
Yes

7. Do your applications use libraries which depend on LAPACK?
Yes

8. Do your applications use a higher-level interface to LAPACK?
No

10. Is the LAPACK procedure interface a barrier to more extensive use?
No

11. From which languages do you call LAPACK routines?
C, C++, Fortran 77, Fortran 90/95

12. Please describe any tools or helper functions that you frequently implement to assist your applications in using LAPACK?
I usually wrap the f77 calls in f90 shells that allocate workspace memory as required.

13. How could the LAPACK interface be improved to feel more natural to your application and implementation language?
Automatic memory allocation for temporary/work arrays would be a nice option. I understand why LAPACK does the whole bit about 'leading dimension of array...' but it's awkward and clumsy. Would be nicer to use f90 interfaces that know what shape the array is, or a simple C++ array type that does as well. (But *not* a complicated C++ array type like Blitz supplies; don't make LAPACK itself dependent on anything!)

14. If you have installed LAPACK yourself, how could the installation process be improved?
The testing process is too slow. It's hard to believe the functionality oculdn't be tested with quicker-running problems. Perhaps have the option of the long test if you want it. A typical scenario is that I get onto some new machine and find I have to install LAPACK, then I can kiss productive time goodbye waiting for the tests to run.

15. How frequently do you refer to the LAPACK Users Guide?
Sometimes

ScaLAPACK Usage

1. Do you use ScaLAPACK (or a vendor version of ScaLAPACK )?
No

2. If you do not use ScaLAPACK, why?
Use another pkg

3. If using another package, which one(s)?
LAPACK

15. How frequently do you refer to the ScaLAPACK Users Guide?

Targeted Environment Specifics

1. Under which operating system environments do your applications run?
Linux, Windows (cygwin)

3. If your applications run in a distributed-memory environment, which styles of parallelism do they employ?
Message passing

Additional Information