# How can I manipulate with fields in structure.

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Kiryl Zhaliazka on 4 Mar 2022
Answered: Jan on 4 Mar 2022
I have struct s with 96 fields that have different names, each field is 44x1 column of numbers.
is it possible to divide all numbers in each field by some number, or use reshape to make from 44*1 to 11*4 matrix, or for example find max from each field and make a new array from those maximum values.

Voss on 4 Mar 2022
You can use structfun() for that:
% creating a struct like yours but with only 3 fields:
s = struct('field1',zeros(44,1),'field2',ones(44,1),'field3',randn(44,1))
s = struct with fields:
field1: [44×1 double] field2: [44×1 double] field3: [44×1 double]
% divide by 7:
s_new = structfun(@(x)x/7,s,'UniformOutput',false)
s_new = struct with fields:
field1: [44×1 double] field2: [44×1 double] field3: [44×1 double]
s_new.field2
ans = 44×1
0.1429 0.1429 0.1429 0.1429 0.1429 0.1429 0.1429 0.1429 0.1429 0.1429
% reshape:
s_new = structfun(@(x)reshape(x,11,4),s,'UniformOutput',false)
s_new = struct with fields:
field1: [11×4 double] field2: [11×4 double] field3: [11×4 double]
% get the max:
s_max = structfun(@max,s)
s_max = 3×1
0 1.0000 2.6450
##### 2 CommentsShowHide 1 older comment
Voss on 4 Mar 2022
You're welcome!

### More Answers (1)

Jan on 4 Mar 2022
A loop over the field names can achieve this:
s = struct('field1',zeros(44,1),'field2',ones(44,1),'field3',randn(44,1)); % Thanks _
Field = fieldnames(s);
for k = 1:numel(Field)
s.(Field{k}) = s.(Field{k}) / 17;
% Or: s.(Field{k}) = reshape(s.(Field{k}), 4, 11);
end
This is done in structfun also, but the loop runs faster and is easier to read, in my opinion.