Calling FFTS c functions from Julia

Julia FFTS.jl

# Complex transforms
# Sign argument
#   -1  = Complex to Complex reverse FFT
#   1   = Complex to Complex forward FFT

# ffts_plan_t *ffts_init_1d(size_t N, int sign); 
# Create a plan for a forward 1D FFT of size 16 
N         = 2^16
Direction = 1 
ffts_plan = ccall((:ffts_init_1d, "libffts"), Ptr{Void}, (Csize_t, Cint), N, Direction)

# ffts_execute(ffts_plan_t * , const void *input, void *output)
#   Create a dirac delta signal and execute the FFT using the ffts_plan
input    = zeros(Complex64, N)
input[1] = 1
output   = zeros(Complex64, N)
ccall((:ffts_execute, "libffts"), Void, (Ptr{Void}, Ptr{Void}, Ptr{Void}), ffts_plan, input, output)
display(output)

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# Free the plan from c memeory
ccall((:ffts_free, "libffts"), Void, (Ptr{Void},), ffts_plan)

# ffts_plan_t *ffts_init_2d(size_t N1, size_t N2, int sign);
#   Create a plan for a forward 2D FFT of size [16, 182]
N         = 16
Direction = 1 
ffts_plan = ccall((:ffts_init_2d, "libffts"), Ptr{Void}, (Csize_t, Csize_t, Cint), N, N, Direction)

# ffts_plan_t *ffts_init_nd(int rank, size_t *Ns, int sign);
#   Create a plan for a forward 3D FFT of size [16, 16, 16]
Ns        = Csize_t[16, 16, 16]
Rank      = 3
Direction = 1
ffts_plan = ccall((:ffts_init_nd, "libffts"), Ptr{Void}, (Cint, Ptr{Csize_t}, Cint), Rank, Ns, Direction)