DADiSP Worksheet Functions > Function Categories > Data Manipulation and Editing > DELAY

 

DELAY

Purpose:

Offsets a series by n number of points along the x-axis.

Syntax:

DELAY(series, n)

series

-

A series or table.

n

-

A positive integer, the number of points to offset the input series.

Returns:

A series or table.

Example:

W1: 1..3

W2: delay(w1, 2)

 

Offsets W1 by two points by prepending two zeros. The resulting series contains the values {0, 0, 1, 2, 3}.

Example:

W1 - delay(W1, 1)

 

Returns a series containing the difference in y-values between each point and the previous point.

Remarks:

DELAY effectively moves a series n points to the right by setting the first n points of the new series to zero. The remaining point values of the new series are set according to the following relation:

 

image\delay01.gif

 

Point n+1 of the delayed series is equal to the first point of the original one.

 

image\delay02.gif

 

The delay amount can only be specified as a positive integer number of points. For example:

 

delay(W1,floor(4.2/deltax(W3)))

 

DELAY is useful for creating finite impulse response (FIR) filters.

 

See EXTRACT to prepend a series with zeros and preserve the original origin.

 

See CIRCSHIFT to circularly shift a series.

 

See SETXOFFSET to set the starting location in terms of X units.

See Also:

CIRCSHIFT

EXTRACT

REVERSE

SETXOFFSET