iir_cheby2 (MathScript RT Module Function)

Owning Class: filter design

Requires: MathScript RT Module

Syntax

[b, a] = iir_cheby2(n, db, w)

[b, a] = iir_cheby2(n, db, w, 's')

[b, a] = iir_cheby2(n, db, [w1, w2])

[b, a] = iir_cheby2(n, db, [w1, w2], 's')

[b, a] = iir_cheby2(n, db, w, option)

[b, a] = iir_cheby2(n, db, w, option, 's')

[b, a] = iir_cheby2(n, db, [w1, w2], 'stop')

[b, a] = iir_cheby2(n, db, [w1, w2], 'stop', 's')

[z, p, k] = iir_cheby2(n, db, w)

[z, p, k] = iir_cheby2(n, db, w, 's')

[z, p, k] = iir_cheby2(n, db, [w1, w2])

[z, p, k] = iir_cheby2(n, db, [w1, w2], 's')

[z, p, k] = iir_cheby2(n, db, w, option)

[z, p, k] = iir_cheby2(n, db, w, option, 's')

[z, p, k] = iir_cheby2(n, db, [w1, w2], 'stop')

[z, p, k] = iir_cheby2(n, db, [w1, w2], 'stop', 's')

[as, bs, cs, ds] = iir_cheby2(n, db, w)

[as, bs, cs, ds] = iir_cheby2(n, db, w, 's')

[as, bs, cs, ds] = iir_cheby2(n, db, [w1, w2])

[as, bs, cs, ds] = iir_cheby2(n, db, [w1, w2], 's')

[as, bs, cs, ds] = iir_cheby2(n, db, w, option)

[as, bs, cs, ds] = iir_cheby2(n, db, w, option, 's')

[as, bs, cs, ds] = iir_cheby2(n, db, [w1, w2], 'stop')

[as, bs, cs, ds] = iir_cheby2(n, db, [w1, w2], 'stop', 's')

Legacy Name: cheby2

Description

Designs a Chebyshev filter of type 2. If you specify w, this function generates a lowpass filter of order n. If you specify w1 and w2, this function generates a bandpass filter of order 2n. [z, p, k] and [as, bs, cs, ds] generate the zero-pole-gain representation and the state-space representation, respectively, of the filter.

Examples

Inputs

Name	Description
n	Specifies the filter order. n is a nonnegative integer.
db	Specifies the decibel value of the peak-to-peak ripple in the passband. db is a real number.
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. 'low' (default) Designs a lowpass filter. 'high' Designs a highpass filter.
'stop'	Directs LabVIEW to design a stopband filter. If you do not specify 'stop' and you specify w1 and w2, LabVIEW designs a bandpass filter.
's'	Directs LabVIEW to design an analog Chebyshev filter of type 2.

Outputs

Name	Description
b	Returns the numerator of the filter under design. b is the forward filter coefficient of order n. b is a real vector.
a	Returns the denominator of the filter under design. a is the backward filter coefficient of order n. a is a real vector.
z	Returns the zeros of the filter. z is a vector.
p	Returns the poles of the filter. p is a vector.
k	Returns the gain of the filter. k is a real number.
as	Returns the A coefficients of the filter. as is a matrix.
bs	Returns the B coefficients of the filter. bs is a matrix.
cs	Returns the C coefficients of the filter. cs is a matrix.
ds	Returns the D coefficients of the filter. ds is a matrix.

Details

The following table lists the support characteristics of this function.

Supported in the LabVIEW Run-Time Engine	Yes
Supported on RT targets	Yes
Suitable for bounded execution times on RT	Not characterized

Examples

N = 5;
DB = 20;
W = 0.4;
[B, A] = iir_cheby2(N, DB, W)

Related Topics

fir_remez
iir_butter
iir_cheby1
iir_cheby2ord
iir_cheby2zpk
iir_elliptic