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Re: moving toward a 3.0 release


From: David Bateman
Subject: Re: moving toward a 3.0 release
Date: Fri, 29 Sep 2006 09:53:54 +0200
User-agent: Thunderbird 1.5.0.7 (X11/20060921)

Joe Koski wrote:
> As a Fortran programmer for 40+ years, I have chased similar bugs. Here are
> some off-the-wall thoughts that may or, more likely, may not help.
>   
I worked with fortran almost exclusively from 1990 to 2000, some in f77
at least I'm fairly fluent. :-)
> You mentioned common blocks. If you are working with routines that were
> converted from 32 bits to 64 bits, or you have mixed 32 bit and 64 bit
> variables, watch the common block declarations, even in routines that are
> not directly involved. Implicit declarations such as real*8 (a-h,o-z) can be
> killers if not applied uniformly in every routine.
>   
I mentioned common blocks as a potential source of a means of altering
the value of j extrenally before eliminating it as although j is "saved"
it isn't in a common block.
> Have you applied the -r8 declaration to gfortran to see if that solves the
> problem?
>   
That is however an idea. It shouldn't help if ARPACK isn't buggy, as
there are both single and double precision versions of all of the
functions. Though something might have slipped through.

> Right now gfortran-4.2 is broken for building octave on Macs, so I have been
> using g95 for that. The g95 compiler seems to be more stable and further
> developed than gfortran. That's just a personal opinion based on compiling
> twenty or thirty different Fortran codes. On the negative side, I don't
> thing g95 gets along that well with gdb.
>   
Too many choices so little time ......

> Good luck. The answer to dilemmas such as these usually came to me while
> jogging at lunch. Walking away usually helps.
>   
I started eigs development about 18 months ago, so I've walked away from
this projet a number of times. I found a bug in my ATLAS build that way,
and got to the point now where in fact the code is almost useful :-)


Thanks for the ideas Joe, I think I'll definitely try the -r8 option and
see if it help..

Cheers
David

-- 
David Bateman                                address@hidden
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