How can I manipulate with fields in structure.

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Kiryl Zhaliazka
Kiryl Zhaliazka le 4 Mar 2022
Réponse apportée : Jan le 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.

Réponse acceptée

Voss
Voss le 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 commentaires
Kiryl Zhaliazka
Kiryl Zhaliazka le 4 Mar 2022
Thank you so much!
Voss
Voss le 4 Mar 2022
You're welcome!
If that answers your question, please consider marking the answer as 'Accepted'. Thanks!

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Plus de réponses (1)

Jan
Jan le 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.

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