fir_pmord (MathScript RT Module Function)
LabVIEW 2011 MathScript RT Module Help
Edition Date: June 2011
Part Number: 373123B-01
»View Product Info
Edition Date: June 2011
Part Number: 373123B-01
»View Product Info
Owning Class: filter design
Requires: MathScript RT Module
Syntax
[n, fb, ab, w] = fir_pmord(f, a, ripple)
[n, fb, ab, w] = fir_pmord(f, a, ripple, fs)
Legacy Name: firpmord
Description
Returns the order and normalized frequencies of the lowest order linear phase FIR filter with a given specification. The designed filter is an optimal equiripple filter that uses the Parks-McClellan algorithm.
Inputs
| Name | Description |
|---|---|
| f | Specifies the cutoff frequencies of the filter. f is a vector of increasing positive numbers in the interval [0, fs/2]. |
| a | Specifies the desired magnitudes at the f frequencies. a is a real vector. |
| ripple | Specifies the maximum deviation of ripples per band. ripple is a real vector. |
| fs | Specifies the sampling frequency. fs is a positive number. The default is 2. |
Outputs
| Name | Description |
|---|---|
| n | Returns the estimated filter order. n is a positive integer. |
| fb | Returns the normalized frequencies corresponding to f. fb is a real vector of increasing values in the interval [0, 1]. |
| ab | Returns the magnitudes of the filter. ab is a real vector of the same size as fb. |
| w | Returns the weights of the filter. w is a vector of positive numbers of the same size as fb. |
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
F = [100, 200];
A = [0, 1];
RIPPLE = [0.05, 0.02];
FS = 500;
[N, FB, AB, W] = fir_pmord(F, A, RIPPLE, FS)