Save for loop outputs into structure

Hi,

I am trying to clean some field data using some function. The data are matrix [n x 16]. I would like to generate a structure into a for loop with substructures per each iteration (in this case, per each column).

Here it's the code I wrote so far:

allBIN = [];

nBin = 16; % Number bins

for n = 1:nBin

allVel = [uAll(:,n) vAll(:,n) w1All(:,n) w2All(:,n)]; %get velocity data from each column from uAll, vAll, w1All and w2All

corr = [corrB1(:,n) corrB2(:,n) corrB3(:,n) corrB4(:,n)]; %get correlation data from each column from corrB1, corrB2, corrB3 and corrB4

% Input necessary for CMA function

start=1;

stop=length(uAll(:,1));

thresh=70;

[x,y,z,x_nan,y_nan,z_nan,cleanCorr,cleanVel]=CMA(corr,allVel,start,stop, timeAll',thresh);

% Save cleanCorr and cleanVel from each iteration into structure

allBIN.('n').corr = cleanCorr;

allBIN.('n').vel = cleanVel;

end

I would like to have an output like:

for n = 1:

allBIN.1.corr

allBIN.1.vel

for n = 2:

allBIN.2.corr

allBIN.2.vel

and so on...

Any suggestion?

Thank you!

[Stephen23]

"I would like to have an output like ... Any suggestion?"

Using a structure array would be simpler and more efficient:

allBIN(1).corr
allBIN(1).vel
..
allBIN(2).corr
allBIN(2).vel
..

https://www.mathworks.com/help/matlab/matlab_prog/access-multiple-elements-of-a-nonscalar-struct-array.html

Answer 1

[Rik]

You should probably use a struct array:

allBIN(n).corr= ___
%etc

But if you insist: field names must be valid variable names, so you need to prepend something:

field=sprintf('it_%d',n);
allBIN.(field).corr= ___
%etc

[carola forlini]

Hi Rik,

Thank you for your help.

My mistake was to not specify a valid variable name.

Answer 2

[Davide Masiello]

Does

allBIN(n).corr

work?

[carola forlini]

Hi Davide,

I already tried that, and Matlab doesn't allow me to do it.

This is the error message: 'Argument to dynamic structure reference must evaluate to a valid field name'.

Thank you,

Carola

[Stephen23]

"This is the error message: 'Argument to dynamic structure reference must evaluate to a valid field name'."

The indexing that Davide Masiello showed will not throw that error. It works without error:

n = 2;
A(n).corr = pi

A = 1×2 struct array with fields:
    corr

A(n).corr

ans = 3.1416

However if you try to set a fieldname using an invalid field (e.g. using a numeric) you will get that error:

B.(2).corr = pi

Argument to dynamic structure reference must evaluate to a valid field name.

[Davide Masiello]

I concur with Stephen.

[carola forlini]

Thank you everyone for all the explanations.