how to decimate the signal in matlab

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prcken

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Hi, I am using Matlab and Delta-Sigma toolbox to simulate the system below

I can get the signal after being filtered as shown in the figure below

the vout in the plot is not the final output. I think the final output should be decimated digital output. does anybody know how to do the decimation in Matlab?
Thanks!
 

I tried vout = vout(1:OSR:end); and vout = resample(vout,1,OSR);
both can do decimation.
but both return a vector length which is the (original vector length) /OSR, such that i couldn't overlay and compare it to the signals before decimation.

and another thing is the decimated output is not digital signal by using this Matlab command. I think it also needs a compactor kind of function

I am not sure if I said my problem clear.
 
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Basically, decimation algorithms reduce number of samples. The length of the vector is smaller, but the time vector has greater dt.
I'm not sure what result do You want to get.
While You decimate the signal, You will get the same shape of the curve, with the smaller number of samples.
If you want to decimate signal, and keep the old dt (fs) (compress signal in time domain ), then You should add zeros at the end of the vector.
But I don't think that is a good idea.
 

yes, you are absolutely right.
I've solved the problem by using repmat command in the matlab. and can only represent in decimal format in the time-domain plot, basically like a sample and hold. from the PSD plot, seems correct. please check the picture below

 

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