ISCE_INSAR/components/isceobj/Util/src/fourn.F

26 lines
577 B
Fortran

subroutine fourn(data,nn,ndim,isign)
complex data(*), d(16384)
integer nn(2),n,ndim,is
is = -isign
n = nn(1)
do i = 1 , nn(1)
call cfft1d_jpl(nn(2),data(1+nn(2)*(i-1)),is)
end do
do i = 1 , nn(2)
do j = 1 , nn(1)
d(j) = data(i+nn(2)*(j-1))
end do
call cfft1d_jpl(nn(1),d,is)
do j = 1 , nn(1)
if(is .eq. 1)then
d(j) = d(j)*nn(1)*nn(2)
endif
data(i+nn(2)*(j-1)) = d(j)
end do
end do
return
end