dftMatrix: Create a n-by-n discrete Fourier transform matrix.
In romanflury/mrbsizeR: Scale Space Multiresolution Analysis of Random Signals

Description Usage Arguments Details Value Examples

The discrete Fourier transform (DFT) matrix for a given dimension n is calculated.

1	dftMatrix(n)

`n`	Dimension for the DFT matrix.

The DFT matrix can be used for computing the discrete Fourier transform of a matrix or vector. dftMatrix(n) %*% testMatrix is the same as apply(testMatrix, MARGIN = 2, FUN = fft).

The n-by-n DFT matrix.

set.seed(987)
testMatrix <- matrix(sample(1:10, size = 25, replace = TRUE), nrow = 5)
D <- dftMatrix(5)

# Discrete Fourier transform with matrix multiplication:
D %*% testMatrix 

# Discrete Fourier transform with function fft: 
apply(testMatrix, MARGIN = 2, FUN = fft)