How to calculate the moving average of a finite duration data using sliding concept?

I want to compute the moving average of the data array as X = [2 3 4 5 6 8] using sliding window concept with window size of 4. This example is given in the following link. https://in.mathworks.com/help/dsp/ug/sliding-window-method-and-exponential-weighting-method.html .

For that, I am using the command movAvg = dsp.MovingAverage from DSP System Toolbox. But using that I am getting answer like as shown below.

X = [2 3 4 5 6 8];
movavgWindow = dsp.MovingAverage(4);
Y = movavgWindow(X)

Y = 1×6

0.5000 0.7500 1.0000 1.2500 1.5000 2.0000

But as per the link given above the actual answer would be like as shown below.

Y = [0.5 1.25 2.25 3.50 4.50 5.75];

So where is the mistake? Can anyone tell me why the answer is comming as so different even if I am using the same command as recommended in the documemt.

Answer 1

[Matt J]

Both are wrong.

X = [2 3 4 5 6 8];

win=ones(1,4)/4;

Y = conv(X,win,'full')

Y = 1×9

0.5000 1.2500 2.2500 3.5000 4.5000 5.7500 4.7500 3.5000 2.0000

[Souarv De]

@Matt J I have two follow up questions based on your answer. (1) It is really so shocking that how the MATLAB inbult command can give wrong answers or there may be some mistake we are doing to understand about how the functions works.

(2) You have done a full convolution over the data samples and thats correct, I agree. Thanks for the help. But if we think it like this way that at each instant one data samples comes in into the data array and we have to evalute the moving average using the slidling window upto the sequence of that sample only (as here n = 6), then how the above command line would get modified. What I mean to say is I donot want to pad zeros after X(6) = 8 as the window is covered all the data samples when n = 6. So we should stop it here. Then how to do this except selecting the range of Y from 1 to 6. Is there any way to do that?

[Matt J]

It is really so shocking that how the MATLAB inbult command can give wrong answers or there may be some mistake we are doing to understand about how the functions works.

Probably the latter, but I can't tell from the documentation what it's doing.

Then how to do this except selecting the range of Y from 1 to 6. Is there any way to do that?

One way:

X = [2 3 4 5 6 8];

Y=movmean(X,[3,0],'Endpoints',0)

Y = 1×6

0.5000 1.2500 2.2500 3.5000 4.5000 5.7500

[Souarv De]

@Matt J Thanks Matt for helping me to understand the solution.