# convcirc (MathScript RT Module Function)

LabVIEW 2012 MathScript RT Module Help

Edition Date: June 2012

Part Number: 373123C-01

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Owning Class: filter implementation

Requires: MathScript RT Module

## Syntax

x = convcirc(a, b)

x = convcirc(a, b, n)

Legacy Name: `cconv`

## Description

Computes the circular convolution of two input vectors.

Details

Examples

## Inputs

Name Description
a Specifies a real or complex input vector. If length(a) is greater than n, LabVIEW wraps a. If length(a) is less than n, LabVIEW pads the end of a with zeros.
b Specifies a real or complex input vector. If length(b) is greater than n, LabVIEW wraps b. If length(b) is less than n, LabVIEW pads the end of b with zeros.
n Specifies the size of the circular convolution. The default is length(a) + length(b) - 1.

## Outputs

Name Description
x Returns the circular convolution of a and b.

## Details

LabVIEW computes the circular convolution using the same algorithm as the default method in the Convolution VI. However, you can use the convcirc function to set the size of the convolution whereas the Convolution VI always returns the result with a length of length(a) + length(b) - 1.

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

a1 = 0.1:0.1:0.4;
b1 = mirrorh(a1);
x1 = convcirc(a1,b1);

a2=[1-j, 2+2j, 3-3j, 4+4j];
b2=[5+0.5j, 4-0.4j, 3+3j, 2, 1];
x2 = convcirc(a2, b2, 4);