SignalProcessing
DownSample
down-sample a signal
Calling Sequence
Parameters
Options
Description
Thread Safety
Examples
Compatibility
DownSample( A, factor, phase )
A
-
Array of real or complex values; the signal
factor
posint, down-sample factor
phase
nonnegint, (optional) phase
container : rtable, predefined Array for holding results
The DownSample( A, factor, phase ) command down-samples the signal in the Array A.
The effect of this command is to copy one sample from each block of factor samples in A to the output.
Before the code performing the computation runs, Maple converts A to a hardware datatype, first attempting float[8] and subsequently complex[8], unless it already has one of these datatypes. For this reason, it is most efficient if A has one of these datatypes beforehand.
The phase argument determines an offset, so that the sample value from A occurs phase positions offset in the output array. The value of phase must be non-negative and less than the value of factor.
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 iquo( N + factor - 1 - phase, factor ) where N is the number of elements of A, and it must have datatype float[8] if A is real and complex[8] if A is complex.
The SignalProcessing[DownSample] command is thread-safe as of Maple 17.
For more information on thread safety, see index/threadsafe.
with⁡SignalProcessing:
A ≔ Array⁡1,2,3,4,5,6,7,8,9,'datatype'='float'8
A≔1.2.3.4.5.6.7.8.9.
DownSample⁡A,1
1.2.3.4.5.6.7.8.9.
DownSample⁡A,2
1.3.5.7.9.
DownSample⁡A,3
1.4.7.
DownSample⁡A,4
1.5.9.
DownSample⁡A,3,0
DownSample⁡A,3,1
2.5.8.
DownSample⁡A,3,2
3.6.9.
C ≔ Array⁡1..4,'datatype'='float'8:
DownSample⁡A,2,1,'container'=C
2.4.6.8.
C
The SignalProcessing[DownSample] command was introduced in Maple 17.
For more information on Maple 17 changes, see Updates in Maple 17.
See Also
UpSample
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