d=gabframediag(g,a,M,L); d=gabframediag(g,a,M,L,'lt',lt);
g | Window function. |
a | Length of time shift. |
M | Number of channels. |
L | Length of transform to do. |
lt | Lattice type (for non-separable lattices). |
d | Diagonal stored as a column vector |
gabframediag(g,a,M,L) computes the diagonal of the Gabor frame operator with respect to the window g and parameters a and M. The diagonal is stored a as column vector of length L.
The diagonal of the frame operator can for instance be used as a preconditioner.