# how to obtain the mean for single variable/location of a multiple 3d .mat file ?

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Hanisah noh on 27 May 2020
Commented: Ameer Hamza on 28 May 2020
i have 240 files of 3dimension .mat files with 140x122x118
i have obtain the mean of these files using this method (credits to matlab community):
...
files=dir('*.mat');
totalfile = numel(files);
C = cell(1,totalfile);
for a = 1:totalfile
C(a) = struct2cell(T);
end
M = cat(4,C{:})
M(isnan(M))=0 % replace NaN to 0
ave = mean(M,4) % mean of the 4th dimension
however,
how do i obtain the mean of a single location/variable from all these 240 files, eg: location{100,10,50} ?
thank you

Ameer Hamza on 27 May 2020
Something like this
files=dir('*.mat');
totalfile = numel(files);
V = zeros(1,totalfile);
for a = 1:totalfile
C = struct2cell(T);
V(a) = C{1}(100,10,50)
end
V(isnan(V))=0 % replace NaN to 0
ave = mean(V)

Hanisah noh on 27 May 2020
thank you Ameer Hamza
what does {1} indicates ?
..
V(a) = C{1}(100,10,50)
..
Ameer Hamza on 28 May 2020
It is chained indexing in MATLAB. Normally chained indexing is not allowed in MATLAB because parenthesis are used both for functions and indexing. However, for cell arrays, chained indexing is allowed.