Unable to perform assignment because the left and right sides have a different number of elements

Hello,

I want to separate this char string into groups of 4 letters.

cadena='0045003e003500440045003e003500440041003f00430040004f'

r_num=num2str(zeros(length(cadena),1));

for i=1:length(cadena)
    r_num(i)=cadena(i);   % I create a column array which contains the components separately
end

seccion=num2str(zeros(ceil(length(cadena)/4),1));
for j=1:length(cadena)-4
    seccion(j)=strcat(r_num(j),r_num(j+1),r_num(j+2),r_num(j+3));  %then I tried to join the components again in groups of four
    j=j+4;
end

However, an error appeared:

Unable to perform assignment because the left and right sides have a different number of elements.

Error in Untitled4 (line 14)
seccion(j)=strcat(r_num(j),r_num(j+1),r_num(j+2),r_num(j+3));

(I also have tried to use strsplit or strtok functions, but they are for texts separated by commas)

If you find the solution, or a better way of doing it, please help me

Thanks

Answer 1

[Ameer Hamza]

seccion(j) is an element of a scalar array. It can only hold a single character. If you want to store multiple characters, then you should use cell arrays. Check the following code. I have also fixed a few other issues. I have also given a one-liner version of your code, which avoids all these for loops

cadena ='0045003e003500440045003e003500440041003f00430040004f';
r_num=num2str(zeros(length(cadena),1));
for i=1:length(cadena)
    r_num(i)=cadena(i);   % I create a column array which contains the components separately
end
seccion=cell(ceil(length(cadena)/4),1);
for j=1:4:length(cadena)
    seccion{(j+3)/4}=strcat(r_num(j),r_num(j+1),r_num(j+2),r_num(j+3));  %then I tried to join the components again in groups of four
end

One-liner:

cadena ='0045003e003500440045003e003500440041003f00430040004f';
seccion = mat2cell(cadena, 1, 4*ones(1,numel(cadena)/4)).';

Access elements of cell array like this

seccion{1}
seccion{2}
..
..
seccion{end}