winsinc

Applies a windowed sinc filter

USAGE:
[xf,Rh,Fh] = winsinc(x,dt,fc,ns,ftype,fo)

DESCRIPTION:
Windowed Sinc Filter. This is a digital symetric non-recursive filter which can be Lowpass, Highpass, or Bandpass by using a windowed sinc function.Non-Recursive filters are based on convolving the input series with a weight function.Their advantage compared to recursive filters is that they are always stable and matematically simpler.Their disadvantage is that they may require a large number of weights to achieve a desired response.

INPUT VARIABLES:
x = vector
dt = Sampling Interval
fc = Cutoff frequency
ns = Width of filter
(>>ns produces a steeper cutoff
but is more computationally expensive)
2*ns + 1 = Order of Filter, (Number of Filter Coef.)
win = Window Type:
'welch','parzen','hanning','hamming'
'blackman','lanczos','kaiser'

ftype = 'low', 'high' o 'pass'
fo = Central Frequency (for bandpass only)

OUTPUT VARIABLES:
xf = filtered vector
Rh = Filter Response
Fh = Frequencies for Filter Response