How do I fix error: Index exceeds matrix dimensions?

I want to make a loop where I calculate the mean of my 35040x12datamatrix for every 24 datapoint, but I get an error: Error using dataset/subsref (line 616) Index exceeds matrix dimensions.

for i=1:24:35040
Xday(icount,:)=mean(A.data(i:24*i,:));
icount=icount+1;
end

What am I doing wrong? Thanks

Answer 1

[James Tursa]

Try this:

for i=1:24:35040
Xday(icount,:)=mean(A.data(i:(i+23),:));  % <-- Changed 24*i to i+23
icount=icount+1;
end

Or a vectorized way:

Xday = reshape(mean(reshape(A.data,24,[])),1460,[]);

Answer 2

[Lilja Dahl]

Fantastic! The loop didn't work but vector did! thank you so much

[James Tursa]

For the loop, did you preallocate Xday? E.g., Xday = zeros(1460,12). And did you initialize icount = 1?

[Lilja Dahl]

Thank you so much for your help. My loop ended up looking like this:

icount=1;
for i=1:24:35040
Xday(icount,:)=missmean(Anew0.data(i:icount*24,:));
icount=icount+1;
end