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Member of the filter design class.

Syntax

b = fir1(n, w)

b = fir1(n, w, option)

b = fir1(n, [w1, w2], window)

b = fir1(n, [w1, w2], option, window)

Description

Uses the window design method to design a linear phase FIR filter. This function windows the impulse response with a Hamming window by default.

Examples

Inputs

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.
w	Specifies the cutoff frequency of the filter. w is real number between 0 and 1. 1 represents the Nyquist frequency.
w1	Specifies the low cutoff frequency. w1 must fall in the range [0, 1].
w2	Specifies the high cutoff frequency. w2 must fall in the range [0, 1] and must be greater than w1.
option	Specifies the type of filter to design. option is a string that accepts the following values. 'bandpass' Designs a bandpass filter. 'low' (default) Designs a lowpass filter. 'high' Designs a highpass filter. 'noscale' Directs LabVIEW not to scale the filter coefficients. 'scale' Directs LabVIEW to scale the filter coefficients. 'stop' Designs a stopband filter.
window	Specifies the window coefficients. The length of window must equal n + 1. If n is even and the filter has a non-zero gain at the Nyquist frequency, the length of window must equal n + 2.

Outputs

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

Examples

N = 5;
W = 0.2;
B = fir1(N, W, 'low', hanning(6))

Related Topics

filter
fir2
firgauss
firls
hamming