How can I manipulate with fields in structure.

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Kiryl Zhaliazka 2022-3-4

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回答： Jan 2022-3-4

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.

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Answer 1

Voss 2022-3-4

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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

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Kiryl Zhaliazka 2022-3-4

Thank you so much!

Voss 2022-3-4

You're welcome!

If that answers your question, please consider marking the answer as 'Accepted'. Thanks!

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Answer 2

Jan 2022-3-4

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在 MATLAB Online 中打开

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