Return the spectral density estimator given a vector of autocovariances c, window name win, and bandwidth, b.
The window name, e.g., "triangle" or "rectangle" is
used to search for a function called win_lw.
If win is omitted, the triangle window is used.
If b is omitted, 1 / sqrt (length (x)) is used.
See also: spectral_xdf.
Package: octave