Hi! Here is a sample pyf file that shows how one can wrap both Fortran LAPACK and ATLAS LAPACK functions with almost the same signatures. Note that callstatement is the latest feature in f2py and right now only available in CVS. The callstatement is quite powerful and allows one to design a wrapper with almost arbitrary Python signature. Here we needed it because sgesv functions in lapack and atlas lapack have different signatures (consider the 'info' argument, for example). Here are the Python signatures of these wrappers: A,ipiv,B,info = f_sgesv(A,B,copy_A=1,copy_B=1) A,ipiv,B,info = c_sgesv(A,B,copy_A=1,copy_B=1) However, a bad news is that lapack and atlas lapack functions are not compatible. For example,
LU,ipiv,X,info=flapack.c_sgesv([[1,2],[3,4]],[1,1]) print LU [[ 2. 0.5] [ 4. 1. ]] print X [-0.5 0.5] LU,ipiv,X,info=flapack.f_sgesv([[1,2],[3,4]],[1,1]) print LU [[ 3. 4. ] [ 0.33333334 0.66666669]] print X [-0.99999994 0.99999994]
Just thought it would be useful you to know some of the latest features in f2py and issues in wrapping lapack and atlas lapack functions. Regards, Pearu !%f90 -*- f90 -*- python module flapack interface subroutine f_sgesv(n,nrhs,A,lda,ipiv,B,ldb,info) fortranname sgesv integer depend(A),intent(hide):: n = shape(A,0) integer depend(B),intent(hide):: nrhs = shape(B,1) real dimension(n,n),check(shape(A,0)==shape(A,1)), intent(in,out,copy) :: A integer intent(hide),depend(n) :: lda=n integer dimension(n),depend(n),intent(out) :: ipiv real dimension(n,nrhs),check(shape(A,0)==shape(B,0)),depend(n),intent(in,out,copy) :: B integer intent(hide),depend(n) :: ldb=n integer intent(out):: info end subroutine sgesv subroutine c_sgesv(n,nrhs,A,lda,ipiv,B,ldb,info) ! ! Here starts ATLAS specific stuff ! fortranname clapack_sgesv intent(c) intent(c) :: c_sgesv callstatement {extern int clapack_sgesv(); info =clapack_sgesv(102,n,nrhs,A,lda,ipiv,B,ldb); } ! ! Here ends ATLAS specific stuff, what follows is identical to above ! integer depend(A),intent(hide):: n = shape(A,0) integer depend(B),intent(hide):: nrhs = shape(B,1) real dimension(n,n),check(shape(A,0)==shape(A,1)), intent(in,out,copy) :: A integer intent(hide),depend(n) :: lda=n integer dimension(n),depend(n),intent(out) :: ipiv real dimension(n,nrhs),check(shape(A,0)==shape(B,0)),depend(n),intent(in,out,copy) :: B integer intent(hide),depend(n) :: ldb=n integer intent(out):: info end subroutine c_sgesv end interface end python module flapack