How to create multiple data structures
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I have two arrays A = {'a';'a';'a';'a';'b';'b';'c';'c';'c';'d';'d'} and B = [1,2,4,6,2,3,4,6,7,8,9]; length(A)=length(B). How can I create a data structure in work space such that a.values = [1,2,4,6], b.values = [2,3], c.values = [4,6,7] and d.values= [8,9]
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Stephen23
el 23 de Jun. de 2018
Editada: Stephen23
el 23 de Jun. de 2018
A much better idea would be to put them into one structure (or cell array):
[U,~,X] = unique(A);
C = accumarray(X(:),B(:),[],@(v){v});
S = struct('values',C)
Then you can simply get the values using basic MATLAB indexing:
S(1).values
S(2).values
... etc
and the corresponding name is given in U:
U{1}
U{2}
... etc
Using indexing is simpler and more reliable than dynamically accessing variable names. Dynamically accessing variable names is one way that beginners force themselves into writing slow, complex, buggy code that is hard to debug. Read this to know why:
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Star Strider
el 23 de Jun. de 2018
If you also want to use your ‘a’, ‘b’, ‘c’, ‘d’ field names in your structure, this works:
A = {'a';'a';'a';'a';'b';'b';'c';'c';'c';'d';'d'};
B = [1,2,4,6,2,3,4,6,7,8,9];
[Au,~,ic] = unique(A);
V = accumarray(ic, B(:), [], @(x){x});
S = cell2struct(V, Au, 1)
S =
struct with fields:
a: [4×1 double]
b: [2×1 double]
c: [3×1 double]
d: [2×1 double]
2 comentarios
Star Strider
el 25 de Jun. de 2018
My pleasure.
My code worked for me (in R2018a). I have no idea what the problem could be, since I do not know what data you are working with. My code does not create any file names.
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