DCT

Purpose:

Calculates the unitary Discrete Cosine Transform.

Syntax:

DCT(series, n)

series	-	An input series or array.
n	-	Optional. An integer, the transform length. Defaults to length(series).

Returns:

A series or array.

Example:

dct(gcos(100, 1/100, 20))

returns a series with a peak at 20 Hz.

Example:

dct(gcos(100, 1/100, 20), 1024)

Same as above, but the input is zero padded to length 1024 before the DCT is calculated.

Remarks:

The unitary discrete cosine transform is define as:

The DCT returns a real result for a real input series.

The transform is applied to each column if the input is an array.

Because relatively few DCT terms can be used to account for a large percentage of series energy, the DCT is often used in signal and image processing applications to perform data compression.

DCT

Purpose:

Syntax:

Returns:

Example:

Example:

Remarks:

See Also: