Matlab function 'movmean' doesn't work on simulink

I'm designing movmean function on simulink using Matlab function block

And when i try to test the block by inputing timeseries data, the input and output of 'movmean' function is same.

I attach pics below

1) Moving Average function block

2) code of Moving Average block

3) input and output of Moving Average block (output is not computed well)

[Ivo]

I have exactly the same problem. :(

Answer 1

[Walter Roberson]

This is expected if the input data is scalar (not a 1 x N or N x 1 vector or 2D array.)

Simulink feeds scalar signals to MATLAB Function Blocks one sample at a time. The moving mean of a scalar alone is the same scalar back again.

Simulink does not keep a history of all the (individually scalar) signals that have gone before, and feed the entire time history into a MATLAB Function Block.

One way to achieve the desired behaviour, is to use a DSP "buffer" block https://www.mathworks.com/help/dsp/ref/buffer.html with the overlap set to one less than the buffer size, and feed the output of the buffer block to a mean block (not a movmean block)

I suspect there might also be methods that involve transfer functions.

[Fangjun Jiang]

There is a "Moving Average" block in DSP toolbox.

[Walter Roberson]

Oh, that is useful!