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SignalProcessing

 TriangleWindow
 multiply an array of samples by a triangular windowing function

 Calling Sequence TriangleWindow(A)

Parameters

 A - Array of real or complex numeric values; the signal

Options

 • container : Array, predefined Array for holding results
 • inplace : truefalse, specifies that output should overwrite input

Description

 • The TriangleWindow(A) command multiplies the Array A by the triangular windowing function and returns the result in an Array having the same length.
 • The triangular windowing function $w\left(k\right)$ is defined as follows for a sample with $N$ points.

$'\mathrm{piecewise}'\left(1\le k\le m,\frac{k}{m},m

 • where $m=\frac{N}{2}$ for even $N$, and $m=\frac{N}{2}-\frac{1}{2}$ for odd $N$.
 • Before the code performing the computation runs, A is converted to datatype float[8] or complex[8] if it does not have one of those datatypes already. For this reason, it is most efficient if A has one of these datatypes beforehand. This does not apply if inplace is true.
 • If the container=C option is provided, then the results are put into C and C is returned. With this option, no additional memory is allocated to store the result. The container must be an Array of the same size and datatype as A.
 • If the inplace or inplace=true option is provided, then A is overwritten with the results. In this case, the container option is ignored.

 • The SignalProcessing[TriangleWindow] command is thread-safe as of Maple 18.

Examples

 > with( SignalProcessing ):
 > N := 1024;
 ${N}{≔}{1024}$ (1)
 > s1 := TriangleWindow( Array( 1 .. N, fill = 1 ) );
 ${{\mathrm{_rtable}}}_{{18446884321097780510}}$ (2)
 > dataplot( s1, style = line );
 > s2 := TriangleWindow( Array( 1 .. N, i -> sin(i*0.1) ) );
 ${{\mathrm{_rtable}}}_{{18446884321097764366}}$ (3)
 > dataplot( s2, style = line );
 >

Compatibility

 • The SignalProcessing[TriangleWindow] command was introduced in Maple 18.