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Downsampling is the process of reducing the sampling rate of a signal. Downsample reduces the sampling rate of the input AOs by an integer factor by picking up one out of N samples. Note that no anti-aliasing filter is applied to the original data. Moreover, a offset can be specified, i.e., the sample at which the output data starts ---see examples below.
Syntaxis
b = downsample(a, pl)
With the following parameters:
Examples
1. Downsampling a sequence of random data at original sampling rate of 10 Hz by a factor of 4 (fsout = 2.5 Hz) and no offset.
x=ao(tsdata(randn(100,1),10)); % create an AO of random data with fs = 10 Hz
pl = plist(); % create an empty parameters list
pl = append(pl, param('factor', 4)); % add the decimation factor
y = downsample(x, pl); % downsample the input AO, x
iplot(x, y) % plot original,x, and decimated,y, AOs
2. Downsampling a sequence of random data at original sampling rate of 10 Hz by a factor of 4 (fsout = 2.5 Hz) and offset = 10.
x=ao(tsdata(randn(100,1),10)); % create an AO of random data with fs = 10 Hz. pl = plist(); % create an empty parameters list pl = append(pl, param('factor', 4)); % add the decimation factor pl = append(pl, param('offset', 10)); % add the offset parameter y = downsample(x, pl); % downsample the input AO, x iplot(x, y) % plot original,x, and decimated,y, AOs
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Signal Pre-processing in LTPDA | Upsampling data | ![]() |
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