freqspace (MATLAB Function Reference)

Determine frequency spacing for frequency response

[f1,f2] = freqspace(n)
[f1,f2] = freqspace([m n])
[x1,y1] = freqspace(...,'meshgrid')
f = freqspace(N)
f = freqspace(N,'whole')

Description

freqspace

returns the implied frequency range for equally spaced frequency responses. freqspace is useful when creating desired frequency responses for various one- and two-dimensional applications.

[f1,f2] = freqspace(n)

returns the two-dimensional frequency vectors f1 and f2 for an n-by-n matrix.

For n odd, both f1 and f2 are [-n+1:2:n-1]/n.

For n even, both f1 and f2 are [-n:2:n-2]/n.

[f1,f2] = freqspace([m n])

returns the two-dimensional frequency vectors f1 and f2 for an m-by-n matrix.

[x1,y1] = freqspace(...,'meshgrid') is equivalent to

[f1,f2] = freqspace(...);
[x1,y1] = meshgrid(f1,f2);

f = freqspace(N)

returns the one-dimensional frequency vector f assuming N evenly spaced points around the unit circle. For N even or odd, f is (0:2/N:1). For N even, freqspace therefore returns (N+2)/2 points. For N odd, it returns (N+1)/2 points.

f = freqspace(N,'whole')

returns N evenly spaced points around the whole unit circle. In this case, f is 0:2/N:2*(N-1)/N.