Re: [Help-glpk] testing glpk 4.46 on 64-bit platform

[Andrew Makhorin]

Hi Robbie,

> My 64-bit system:
> 
>   Ubuntu 10.04 Linux 2.6.32-31-generic
>   2.40GHz Intel Core i5-520M / 4096MiB RAM
>   gcc version 4.4.3
> 
> I just tested GLPK 4.46 as you requested using the file
> WOOD1P.SIF from the NETLIB suite.
> 
>   http://www.numerical.rl.ac.uk/cute/netlib.html
>   ftp://ftp.numerical.rl.ac.uk/pub/cuter/netlib.tar.gz
> 
>   $ ll wood1p.sif
>   -r--r----- 1 robbie users 2288302 Apr 28 19:24 wood1p.sif
> 
> Everything is basically good.  

Thank you very much. (As Russians say: I owe you a bag of beet :)

> But I have the following
> observations.
> 
> 1/ During configuration, I guess this statement is what
> was sought:
> 
>   checking whether to use zlib data compression library... no

I will remove this configure check. It is no longer needed.

> 
> 2/ The 'wood1p.sif' file needed the blank lines removed
> before GLPSOL would process the file.  That could be a
> bit fussy -- at the very least, a message stating that
> blank lines are causing problems would be helpful.

Don't blank lines violate the mps format requirements?

> 
> 3/ Your test 2 gave a small difference on output --
> leading and trailing zeros were added or the decimal
> points were omitted as required (I much prefer the GLPK
> formatting), for example (GLPK second):
> 
>     RHS       TOTALL              1.   BMIN01             .85
>     RHS1      TOTALL               1   BMIN01            0.85

It is impossible to keep the source formatting, because all numeric data
are stored in glp_prob as floating-point numbers. I think this must not
cause serious problems.

> 
> 4/ Finally, and of more concern, GLPSOL ate my file
> when I incorrectly issued these commands:
> 
>   $ ls
>   oops.sif.gz
>   $ ./glpsol --check oops.sif --wmps oops.sif.gz
>   $ ls
>   <nothing!>
> 
> GLPSOL should really not do that!

Glpsol removes all output files specified in the command line before it
starts processing. 


Best regards,

Andrew Makhorin