fir2 (MathScript Function) (Windows, Not in Base Package)

LabVIEW 8.5 Help
August 2007

NI Part Number:
371361D-01

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Member of the filter design class.

Syntax

b = fir2(n, f, a)

b = fir2(n, f, a, w)

Uses frequency sampling to design a linear phase FIR filter. fir2 windows the impulse response with a Hamming window.

Name	Description
n	Specifies the filter order. n is a nonnegative integer. n must be even for filters with a non-zero gain at the Nyquist frequency. If n does not meet this condition, LabVIEW increases n by 1.
f	Specifies the frequencies at which you want to take samples. 1 represents the Nyquist frequency. f is a real vector of ascending values in the interval [0, 1]. length(f) must equal length(a).
a	Specifies the magnitudes at each of the f frequencies. a is a real vector. length(a) must equal length(f).
w	Specifies the symmetric window to apply to the impulse response. w is a real vector of length n + 1.

Name	Description
b	Returns the filter coefficients of order n. b is a real vector.

N = 13;
F = [0, 0.1, 0.5, 0.7, 1];
A = [0, 1, 1, 0, 0];
B = fir2(N, F, A)