fateme.mirjani

07-07-2008, 02:32 AM

Dear all;

I'm going to use rlft3.f90 (3D Fast Fourier transform subroutine in Numerical Recipes in Fortran book)

I have constructed a 100*100*100 mesh as data. (a special Step-Function)

I should call rlft3(data,speg,nn1,nn2,nn3,isign).

-----------------------------------------------------------------------------

SUBROUTINE rlft3(data,speq,nn1,nn2,nn3,isign)

INTEGER isign,nn1,nn2,nn3

COMPLEX data(nn1/2,nn2,nn3),speq(nn2,nn3)

-----------------------------------------------------------------------------

1- I don't understand why for data is written nn1/2 ? I have a 100*100*100 mesh!!! Does it mean for a 100*100*100 mesh the 50*100*100 is necessary?

2- I don't know what should I put instead of speq? If speg is an output , where is the final answer of subroutine put?

When I put the 50*100*100 data as input, I envisage the segmentation fault.

I'm anxiously looking forward your reply and guidlines.

With my best regards,

Fatemeh

I'm going to use rlft3.f90 (3D Fast Fourier transform subroutine in Numerical Recipes in Fortran book)

I have constructed a 100*100*100 mesh as data. (a special Step-Function)

I should call rlft3(data,speg,nn1,nn2,nn3,isign).

-----------------------------------------------------------------------------

SUBROUTINE rlft3(data,speq,nn1,nn2,nn3,isign)

INTEGER isign,nn1,nn2,nn3

COMPLEX data(nn1/2,nn2,nn3),speq(nn2,nn3)

-----------------------------------------------------------------------------

1- I don't understand why for data is written nn1/2 ? I have a 100*100*100 mesh!!! Does it mean for a 100*100*100 mesh the 50*100*100 is necessary?

2- I don't know what should I put instead of speq? If speg is an output , where is the final answer of subroutine put?

When I put the 50*100*100 data as input, I envisage the segmentation fault.

I'm anxiously looking forward your reply and guidlines.

With my best regards,

Fatemeh