# Calling specific cells and averaging

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Edward Lannon on 16 Nov 2020
Commented: Edward Lannon on 16 Nov 2020
Hello,
I have a 3000X3000 matrix. I also have a list of coordinates that I would like to use to indicate which values to select and average all the selected values. I can't seem to do it. I attached an example of a list.
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Edward Lannon on 16 Nov 2020
Sure thing. I would like to average values located in cells within a 3000X3000 matrix. These specific cells within the 3000X3000 do not follow any real pattern, so I constructed a list of coordinates that notes the location of each cell. So, basicaly the list attached has the locations coordinates (rows, colums) for 365 cells within the larged 3000X3000 matrix that I would like to aggragate and compute an average for.

Hrishikesh Borate on 16 Nov 2020
Hi,
I understand that you want to calculate average of elements present at indices stored in the file “VisualVisualTest.mat”. This can be done using following code:-
a = magic(3000); %3000x3000 matrix
visualCordsall = visualTest.VisualVisualCordsall;
indicesMatrix = transpose(reshape(cell2mat(visualCordsall),2,[]));
sz = [3000, 3000];
ind = sub2ind(sz, indicesMatrix(:,1), indicesMatrix(:,2));
avgValue = mean(a(ind));
Where, avgValue stores the average value.
Edward Lannon on 16 Nov 2020
Thank you!