ndrustfft

ndrustfft: n-dimensional complex-to-complex FFT, real-to-complex FFT and real-to-real DCT

This library is a wrapper for RustFFT, RustDCT and RealFft that enables performing FFTs and DCTs of complex- and real-valued data on n-dimensional arrays (ndarray).

ndrustfft provides Handler structs for FFT's and DCTs, which must be provided alongside with the arrays to the respective function (see below) . The Handlers implement a process function, which is a wrapper around Rustfft's process function with additional functionality. Transforms along the outermost axis are in general the fastest, while transforms along other axis' will create temporary copies of the input array.

Implemented transforms

Complex-to-complex

• fft : [ndfft], [ndfft_par]
• ifft: [ndifft],[ndifft_par]

Real-to-complex

• fft_r2c : [ndfft_r2c], [ndfft_r2c_par],

Complex-to-real

• ifft_r2c: [ndifft_r2c],[ndifft_r2c_par]

Real-to-real

• dct1: [nddct1],[nddct1_par]
• dct2: [nddct2],[nddct2_par]
• dct3: [nddct3],[nddct3_par]
• dct4: [nddct4],[nddct4_par]

Parallel

The library ships all functions with a parallel version which leverages the parallel abilities of ndarray.

Example

2-Dimensional real-to-complex fft along first axis

use ndarray::{Array2, Dim, Ix};
use ndrustfft::{ndfft_r2c, Complex, R2cFftHandler};

let (nx, ny) = (6, 4);
let mut data = Array2::<f64>::zeros((nx, ny));
let mut vhat = Array2::<Complex<f64>>::zeros((nx / 2 + 1, ny));
for (i, v) in data.iter_mut().enumerate() {
    *v = i as f64;
}
let mut fft_handler = R2cFftHandler::<f64>::new(nx);
ndfft_r2c(
    &data.view(),
    &mut vhat.view_mut(),
    &mut fft_handler,
    0,
);

License: MIT