FCIRCONV

Purpose:

Performs circular convolution using the FFT method.

Syntax:

FCIRCONV(series1, series2, length)

series1

-

A series or table.

series2

-

A series or table.

length

-

Optional. An integer, the number of points to process. Defaults to the maximum length of the input series.

Returns:

A series or table.

Example:

W1: {1, 2, 3}

W2: {4, 5, 6}

W3: fcirconv(W1, W2)

 

W3 contains the series {31, 31, 28}, the result of the circular convolution of W1 and W2.

Remarks:

Circular convolution is defined as:

 

image\circonv01.gif

 

for periodic x[n] with period N such that:

 

image\circonv03.gif

 

for any integer k.

 

FCIRCONV performs circular convolution by multiplying the FFTs of the input series. This method is faster than CIRCONV for large series.

 

See CIRCONV for a direct time domain implementation.

See Also:

CIRCONV

CONV

FCONV

FFT