SignalProcessing - Maple Programming Help

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SignalProcessing

 Filter
 filter a signal with a finite impulse response filter

 Calling Sequence Filter( A, a, b )

Parameters

 A - Array of real numeric values; the signal to filter a - Array of real numeric values; the Array of IIR coefficients b - (optional) Array of real numeric values; the Array of FIR coefficients

Options

 • container : Array, predefined Array for holding results

Description

 • The Filter( A, a, b ) command filters the signal (sample) in the array A using the IIR coefficients in the array a and the FIR coefficients in the array b. If b is omitted, no FIR filter is applied (there is only a single coefficient, 1).
 • Before the code performing the computation runs, the input Arrays are converted to datatype float if they do not have that datatype already. For this reason, it is most efficient if the input Arrays have this datatype beforehand.
 • 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 size equal to the size of A and having datatype float.

 • The SignalProcessing[Filter] command is thread-safe as of Maple 17.

Examples

 > $\mathrm{with}\left(\mathrm{SignalProcessing}\right):$
 > $\mathrm{with}\left(\mathrm{plots}\right):$
 > $A≔\mathrm{GenerateTone}\left(128,1,0.05,3.0\right):$
 > $a≔\mathrm{Array}\left(1..3,\left[\frac{1}{3},\frac{1}{3},\frac{1}{3}\right],\mathrm{datatype}={\mathrm{float}}_{8},\mathrm{order}=\mathrm{C_order}\right):$
 > $b≔\mathrm{Array}\left(1..1,\left[1\right],\mathrm{datatype}={\mathrm{float}}_{8},\mathrm{order}=\mathrm{C_order}\right):$
 > $B≔\mathrm{Filter}\left(A,a,b\right):$
 > $\mathrm{display}\left(\mathrm{Array}\left(\left[\mathrm{SignalPlot}\left(A\right),\mathrm{SignalPlot}\left(B\right)\right]\right)\right)$  > 

Compatibility

 • The SignalProcessing[Filter] command was introduced in Maple 17.