Name

---

FILTER_WINDOW

Purpose

---

This function returns a desired filter window of desired width.

Category

---

Time Series Analysis

Calling Sequence

---

Result = FILTER_WINDOW( [Width], [Window] )

Optional Inputs

---

Width: The width of the filter window, of type integer.
Window: A string containing the name of the smoothing window to
return. Options are 'boxcar', 'gaussian', 'hanning',
'triangle'. The default is a boxcar window.

Keyword Parameters

---

BOXCAR: Sets the output to a boxcar window. This is the default.
If set to a value, it replaces Width (obsolete option).
DIMENSION: The dimension of the filter, of type integer. The default
is 1.
TRIANGLE: Sets the output to a triangle window. The default is a
boxcar window. If set to a value, it replaces Width (obsolete
option).

Outputs

---

Result: Returns the desired filter window.

Uses

---

-

Procedure

---

This function builds a filter of the desired shape and width, and then
normalises it.

Example

---

Define a two dimensional boxcar window of width 5.
result = filter_window( 5, 'boxcar', dimension=2 )
result should be a 5x5 matrix with 0.04 for all entries.

Modification History

---

  Written by: Daithi A. Stone (stoned@atm.ox.ac.uk), 2000-06-28.
Modified: DAS, 2001-01-29 (fixed odd width bug).
Modified: DAS, 2003-11-18 (added Window input, DIMENSION
keyword, edited style)
Modified: DAS, 2005-08-05 (replaced SUM.PRO use with TOTAL)
Modified: DAS, 2005-10-21 (removed requirement of odd WIDTH)