# How to Exclude Some Fields While Using the Function structfun?

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Rightia Rollmann on 5 Mar 2017
Answered: Jari Braeckman on 7 Sep 2021
A.B.C = [1 2 3];
A.B.D = [3 4 5];
A.B.E = [6 7 8];
How to exclude A.B.E from the calculation and just get the sums of A.B.C and A.B.D (i.e., g = [4 6 8])?
for i = 1 : 3
z = structfun(@(x) x(i), A.B);
g(1, i) = sum(z);
end
g
dpb on 5 Mar 2017
structfun doesn't have an except clause; think you'll have to use dynamic field names and looping to accomplish this programmatically.
The simple answer for the specific case that doesn't generalize well and is probably not the actual question, either, is just
sum([A.B.C;A.B.D])

Guillaume on 5 Mar 2017
I assume this is related to your previous question. First, I'd like to point out that it doesn't look like a structure is the right container for your data. Since you want to do the same operations on all or most the fields, a cell array (or a matrix if the content of the fields is the same size) would be a lot better.
That's also the way to solve this particular problem. You can't do it with structfun.
A.B.C = [1 2 3];
A.B.D = [3 4 5];
A.B.E = [6 7 8];
c = struct2cell(A.B); %convert to cell array. In this particular case, a matrix would work even better
%you can then filter rows (fields) of the cell array any way you want,e .g.
fn = fieldnames(A.B);
filteredc = c(~ismember(fn, {'E', 'G'})); %remove fields 'E' and 'G'
s = sum(cell2mat(filteredc))

Jari Braeckman on 7 Sep 2021
It should work like this
for i = 1 : 3
z = structfun(@(x) x(i), rmfield(A.B,'E'));
g(1,i) = sum(z);
end

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