downsample - Decrease sampling rate by integer factor

Syntax

Description

y = downsample(x,n) decreases the sampling rate of x by keeping every n-th sample starting with the first sample. x can be a vector or a matrix. If x is a matrix, each column is considered a separate sequence.

y = downsample(x,n,phase) specifies the number of samples by which to offset the downsampled sequence. phase must be an integer from 0 to n-1.

Examples

Decrease the sampling rate of a sequence by 3:

x = [1 2 3 4 5 6 7 8 9 10];
y = downsample(x,3)
% y =  1    4    7    10

Decrease the sampling rate of the sequence by 3 and add a phase offset of 2:

y = downsample(x,3,2)
% y = 3    6    9

Decrease the sampling rate of a matrix by 3:

x = [1 2 3; 4 5 6; 7 8 9; 10 11 12];
y = downsample(x,3);

See Also

decimate | interp | interp1 | resample | spline | upfirdn | upsample

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