[Numpy-discussion] f2py: sharing F90 module data between modules

Garry Willgoose garry.willgoose@newcastle.edu...
Thu Feb 14 15:21:04 CST 2008


Pearu,

Ohh Pearu I'm not complaining about deficiencies in f2py ... its a  
great piece of work that makes what I'm doing possible at all. Just  
like most open source software (including my own ;-) there may be  
ways to tweak it to do things that are undocumented.

>> Why is that problem? I can envisage a user that just wants to use the
>> environment without writing any additional fortran modules (and thus
>> may not even have an installed fortran compiler) and if they screw up
>> mod dates on the files (by say a ftp from one machine to another ...
>> for instance on our cluster the compiler is only installed on one
>> machine and only binaries are moved around the cluster) then the
>> environment might want to reassemble (with f2py) the aggregated
>> library because it (erroneously) thinks there is a newer component
>> shared library. This will fail because f2py quits when asked to
>> process ONLY .so files. If I have a trivial fortran file to force
>> f2py then this forces users to have a fortran compiler on their
>> machine, even if they do not want to actually compile a new fortran
>> module component, simply because f2py will not operate unless it is
>> offered at least one fortran file.
>
> This is not a typical task for f2py. f2py is not a general purpose
> linker. It's amazing that f2py could even be used for such a task,
> so I don't think that the above demonstrates any bug of f2py.

Indeed not typical ... as I recognise ... which is why I wondered if  
there was an undocumented way to tweak to do what I want to do (I get  
requests like this on my own software all the time;-).

>
> However, if you are worried about whether users have fortran compilers
> installed then can you assume that they have a C compiler installed?
> If so, then instead of trivial Fortran file try using the following
> trivial .pyf file:
>
> python module dummy
>   interface
>     subroutine dummyfunc()
>       fortranname
>       callstatement ;
>     end subroutine dummyfunc
>   end interface
> end python module dummy
>
> that should force f2py to build a shared library dummy.so
> with no Fortran dependencies.

Perfect ...

>

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Prof Garry Willgoose,
Australian Professorial Fellow in Environmental Engineering,
Director, Centre for Climate Impact Management (C2IM),
School of Engineering, The University of Newcastle,
Callaghan, 2308
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g.willgoose@telluricresearch.com
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====================================================================
"Do not go where the path may lead, go instead where there is no path  
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                           Ralph Waldo Emerson
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