[NumPy-Tickets] [NumPy] #1532: f2py does not respect assumed size arrays of fortran 90

NumPy Trac numpy-tickets@scipy....
Thu Jul 1 00:51:26 CDT 2010

#1532: f2py does not respect assumed size arrays of fortran 90
 Reporter:  ozn          |       Owner:  pearu
     Type:  enhancement  |      Status:  new  
 Priority:  normal       |   Milestone:  2.0.0
Component:  numpy.f2py   |     Version:  1.3.0
 Keywords:               |  
 consider the following fortran 90 file:

 $ cat dsum.f90
 subroutine dsum(b, a, n)
    integer, intent(in) :: n
    real,intent(in) :: a(n)
    real,intent(out) :: b
    do i=1,n
    end do

 subroutine locpt(x0,y0,x,y,xd,yd,n,l,m)
         INTEGER, INTENT(IN)  :: xd,yd,n
         REAL, INTENT(IN)     :: x0, y0, x(:), y(:)
         INTEGER, INTENT(OUT) :: l, m

         print *, x0
         print *, y0
         print *, x
         print *, y
         print *, 'n', n

         call dsum(x0,x,n)
         print *, 'sum', x0

 I compiled the filed with:
 f2py -c -m dsum dsum.f90

 and it crashes with:

 oz@safira2:~/test$ python
 Python 2.5.2 (r252:60911, Jan 24 2010, 14:53:14)
 [GCC 4.3.2] on linux2
 Type "help", "copyright", "credits" or "license" for more information.
 >>> import dsum
 >>> dsum.locpt(2.0,2.0,(2.0,1.0,3.0),(5.0,6.0,8.0),7,7,3)
 Segmentation fault

 if I replace the line declaring the array with:
         REAL, INTENT(IN)     :: x0, y0, x(xd), y(yd)

 no problems occur.

 It would be nice to be able to pass assumed size arrays too.

 on the other hand, f2py is smart enough to conclude the follwoing:

  print dsum2.__doc__
 This module 'dsum2' is auto-generated with f2py (version:2_5237).
   b = dsum(a,n=len(a))
   l,m = locpt(x0,y0,x,y,n,xd=len(x),yd=len(y))

 so, it figures automatically, that xd and yd, should be optional.

 I don't know whether I'd classify it as a bug/feature wish.

 But I hope it would at least be considered.

 Oz N

 I'm using numpy 1.3 on debian lenny.

Ticket URL: <http://projects.scipy.org/numpy/ticket/1532>
NumPy <http://projects.scipy.org/numpy>
My example project

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