[Numpy-discussion] doctest fortran I/O synchronization

[Todd Miller]

Thanks for the work around.  I haven't tried it yet but I've got a
feeling I'm home free...  something along these lines will definitely
work.

Regards,
Todd

On Fri, 2003-10-10 at 12:37, David M. Cooke wrote:
> On Fri, Oct 10, 2003 at 10:17:54AM -0400, Todd Miller wrote:
> > I'm trying to make a doctest to verify that the different flow patterns
> > of f2py interfaces work with different varieties of numarrays (normal,
> > byte-swapped, misaligned, dis-contiguous, type-converted).  I'm trying
> > to test this out under Linux with g77, and (it seems like) I'm having
> > trouble synchronizing the Fortran I/O with Python's C I/O.
> > 
> > Given foo.f:
> > 
> >       subroutine in_c(a,m,n)
> >       real*8 a(n,m)
> > Cf2py intent(in,c) a
> > Cf2py depend(a) ::  n=shape(a,0),  m=shape(a,1)
> >       do j=1,m
> >          do i=1,n
> >             write (6,1) a(i,j)
> >  1          format( $, 1F3.0, ', ')
> >          enddo
> >          print *,''
> >       enddo
> >       end
> > 
> > And given f2py_tests.py:
> > 
> > """
> > >>> foo.in_f(a)
> >  0.,  5., 10.,
> >  1.,  6., 11.,
> >  2.,  7., 12.,
> >  3.,  8., 13.,
> >  4.,  9., 14.,
> > """
> > import foo, numarray
> > 
> > def test():
> >     import doctest
> >     global a
> >     t = doctest.Tester(globs=globals())
> >     a = numarray.arange(15., shape=(3,5))
> >     t.runstring(__doc__, "c_array")
> >     return t.summarize()
> > 
> > I get this:
> > 
> > [jmiller at halloween ~/f2py_tests]$ python f2py_tests.py
> >  0.,  5., 10.,
> >  1.,  6., 11.,
> >  2.,  7., 12.,
> >  3.,  8., 13.,
> >  4.,  9., 14.,
> > *****************************************************************
> > Failure in example: foo.in_f(a)
> > from line #1 of c_array
> > Expected:
> >  0.,  5., 10.,
> >  1.,  6., 11.,
> >  2.,  7., 12.,
> >  3.,  8., 13.,
> >  4.,  9., 14.,
> > Got:
> > *****************************************************************
> > 1 items had failures:
> >    1 of   1 in c_array
> > ***Test Failed*** 1 failures.
> > 
> > Where it appears that the output from the first example somehow escapes
> > the C I/O system I presume doctest is using.  The actual test I'm
> 
> doctest uses Python's I/O system: it assigns a new object to
> sys.stdout. Your code uses Fortran's output, which would go the same
> place a printf in C would: to the program's stdout (file descriptor 1).
> 
> You'd need to run the code in a separate process, and capture the
> output. Something along the lines of this:
> 
> import commands
> def test_f2py():
>     """
>     put your doctest here
>     """
>     output = commands.getoutput('python f2pytest1.py')
>     print output
> 
> Or, set your test up to write output to a file instead of stdout, then
> read that file (that's probably better).
> 
> > writing has multiple examples, and the fortran I/O *does* make it into
> > the doctest after the first example  but remains out of sync.
> 
> It's out of sync because it's not going through Python; Python has
> absolutely no clue that the Fortran code wrote anything.
> 
> -- 
> |>|\/|<
> /--------------------------------------------------------------------------\
> |David M. Cooke                      http://arbutus.physics.mcmaster.ca/dmc/
> |cookedm at physics.mcmaster.ca
> 
> 
> -------------------------------------------------------
> This SF.net email is sponsored by: SF.net Giveback Program.
> SourceForge.net hosts over 70,000 Open Source Projects.
> See the people who have HELPED US provide better services:
> Click here: http://sourceforge.net/supporters.php
> _______________________________________________
> Numpy-discussion mailing list
> Numpy-discussion at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/numpy-discussion
-- 
Todd Miller 			jmiller at stsci.edu
STSCI / ESS / SSB