GSP_JFT - Compute the Joint time-vertex Fourier Transform

Usage

Xhat = gsp_jft(G,X)

Input parameters

`G`	Time-Vertex graph structure
`X`	Time-Vertex signal

Output parameters

Xhat

Joint Time-Vertex Fourier Transform of X

Description

'gsp_jft(G,X)' computes the joint time-vertex Fourier transform of the time-vertex: signal \(X\) with respect to the Fourier basis of the graph G: U_G and the DFT basis U_T.

To compute the Fourier basis of a graph G, you can use the function:

G = gsp_compute_fourier_basis(G);

Example:

N = 50; T=200;
G = gsp_sensor(N);
G = gsp_jtv_graph(G,T);
G = gsp_compute_fourier_basis(G);
X = sin((1:N)'*(1:T)*pi/(4*N));
Xhat = gsp_jft(G,X);
imagesc(fftshift(abs(Xhat),2));