[Numpy-discussion] F2PY and multi-dimension arrays

Backing Olof

2015-07-01 11:30:12 UTC

Hello,
the project is already successfully completed, but I thought for the completeness (and documentation) give myself an answer on what I did wrong and what the correct solution was.

I. I didn’t realise that parameter ordering was crucial. Somehow I just had forgotten this knowledge, but not matter why I did. So after some talk with my colleagues I did finally sort that out.

II. You can integrate Python and FORTRAN in two different ways: inline with Cf2py or with signature files. The Numpy and f2py documentation describes the Cf2py solution very well. But my project asked for *no* modification of the FORTRAN source files. So I had to enter the undocumented arena.

Lesson learnt: When using the signature file option f2py will effectively re-sort all the parameters in the following order:

* integer
* real
* character
* real dimension

Post by Backing Olof

print (func.___doc___)

If I only had known this in the beginning… ;)

Al the best,
Olof Backing
—
Olof Backing
Sr Open Source Specialist

Combitech AB
Box 1004 • SE-164 21 KISTA • Sweden
Visiting address Torshamnsgatan 30C
Phn +46 8 580 861 95 • Mobile +46 73 437 61 95

Post by Backing Olof
Hi
C Bergstrom FCC
C User subroutine VUMAT
subroutine VUMAT(
C Read only -
* nblock, ndir, nshr, nstatev, nprops,
* stepTime, dt,
* props,
* density, strainInc,
* tempOld,
* stressOld, stateOld, enerInternOld, enerInelasOld,
C Write only -
* stressNew, stateNew, enerInternNew, enerInelasNew )
C
include 'vaba_param.inc'
C
dimension props(nprops),
1 density(nblock), strainInc(nblock,ndir+nshr),
2 tempOld(nblock),
5 stressOld(nblock,ndir+nshr), stateOld(nblock,nstatev),
6 enerInternOld(nblock), enerInelasOld(nblock),
2 stressNew(nblock,ndir+nshr), stateNew(nblock,nstatev),
3 enerInternNew(nblock), enerInelasNew(nblock)
* Corresponding .pyf
integer :: nblock
integer :: ndir
integer :: nshr
integer :: nstatev
integer :: nprops
real :: steptime
real :: dt
real dimension(nprops) :: props
real dimension(nblock) :: density
real dimension(nblock,ndir+nshr) :: straininc
real dimension(nblock) :: tempold
real dimension(nblock,ndir+nshr) :: stressold
real dimension(nblock,nstatev) :: stateold
real dimension(nblock) :: enerinternold
real dimension(nblock) :: enerinelasold
real dimension(nblock,ndir+nshr),intent(out) :: stressnew
real dimension(nblock,nstatev),intent(out) :: statenew
real dimension(nblock),intent(out) :: enerinternnew
real dimension(nblock),intent(out) :: enerinelasnew
nblock = 1
ndir = 3
nshr = 3
nstatev = 3
nprops = 11
stepTime = 1
dt = 1
props = np.array([10, 0.5, 1e10, 5, 1e12, 3e-6, 8e-6, 27, 2], float)
density = np.array([[7.8e3]], float)
strainInc = np.array([[1,-0.5,-0.5,0,0,0]], float)
tempOld = np.array([[1]], float)
stressOld = np.array([[1,1,1,1,1,1]], float)
stateOld = np.array([[1,1,1]], float)
enerInternOld = np.array([1], float)
enerInelasOld = np.array([1], float)
stressNew = np.array([[]], float)
stateNew = np.array([[]], float)
enerInternNew = np.array([[]], float)
enerInelasNew = np.array([[]], float)
stressNew, stateNew, enerInternNew, enerInelasNew = vumat(nblock, ndir, nshr, nstatev, nprops, stepTime, dt, props, density, strainInc, tempOld, stressOld, stateOld, enerInternOld, enerInelasOld)
unexpected array size: new_size=4, got array with arr_size=1
File "./demo.py", line 33, in <module>
main()
File "./demo.py", line 30, in main
stressNew, stateNew, enerInternNew, enerInelasNew = vumat(nblock, ndir, nshr, nstatev, nprops, stepTime, dt, props, density, strainInc, tempOld, stressOld, stateOld, enerInternOld, enerInelasOld)
VUMAT_Bergstrom_FCC.error: failed in converting 9th argument `stressold' of VUMAT_Bergstrom_FCC.vumat to C/Fortran array
* python 2.7.6
* numpy/f2py 1.8.2
* gcc/gfortran 4.8.2
* ubuntu 14.04 LTS 32-bit
I have tried to google, read the f2py manual, fortran tutorials etc, but to no avail. I must also admit that my knowledge in python is so-so and fortran even less(!). What is the missing statement/syntax that I can’t get correct?
Your humble programmer, Olof