Hello,
I would like to use ApproxFun.jl for a truncated FFT. Is it possible to create direct and inverse Fourier transforms spanned by a sparse basis?
This is what I have in mind:
using ApproxFun
S = Fourier()
n = 256
sparse_idx = [1; 20; 30; 40]
T = ApproxFun.plan_transform(S, n)
Ti = ApproxFun.plan_itransform(S, n)
T_sparse = ApproxFun.plan_transform(S, n, sparse_idx)
Ti_sparse = ApproxFun.plan_itransform(S, n, sparse_idx)