This might not be the right place to ask this, but I'm hoping someone can explain two of the arguments in the MATLAB fir2
function. It is a function for designing filters using the frequency sampling method. There are two optional arguments:
npt - Number of grid points, specified as a positive integer scalar. npt must be larger than one-half the filter order: npt > n/2.
lap - Length of region around duplicate frequency points, specified as a positive integer scalar.
I am struggling to find any meaningful literature around this so if anyone could explain these two in further detail or point me to something to read that would be greatly appreciated.