how can convert string to matrix?

i have 'abcb' in output but i want a b c b in output.i need matrix in output.

if true
 clc;
clear all;
u=randi(3,1000,4);
for j=1:4

    for i=1:1000

        if u(i,j)==1
            U(i,j)='a';
        elseif u(i,j)==2
                U(i,j)='b';
            else 
                U(i,j)='c'; 
        end
    end

end

end

[Stephen23]

"i have 'abcb' in output but i want a b c b in output.i need matrix in output"

The character vector 'abcb' is a matrix already:

>> U = 'abcb';
>> ismatrix(U)
ans = 1

It is not clear what the problem, or what you think a matrix is (apart from the one that you already have).

[hesam gharaei]

'abcb' is not separate.i need matrix with 1000 row and 4 column.

[Stephen23]

"'abcb' is not separate"

The character vector 'abcb' consists four separate characters, which are easily accessible using indexing. Each character is one element of the char array, in exactly the same way that a numeric array has separate elements (e.g. four elements in this example):

[1,2,3,1]

It is not clear what you want, or what you expect to see. What you have shown is a character vector and requested that it should be a matrix (it is already), and that you want it to be "separate" (each character is a separate element of the character array). What you showed in your question "...i want a b c b in output" could be achieved by adding space characters into the character vector, or perhaps by using a cell array (but that would pointlessly complicate things). It is not clear how you think a character array should be like (other than simply containing the characters (which is what they do)), or why those spaces are so important (i.e. how are you going to process this data?).

Answer 1

[madhan ravi]

str2sym(U) %at the end

[madhan ravi]

make sure you have symbolic toolbox

Answer 2

[Stephen23]

Get rid of the nested loops, they are not an effective use of MATLAB.

It is much simpler and more efficient to use basic indexing:

>> u = randi(3,1000,4);
>> v = 'abc';
>> m = v(u);
>> m(1:10,:) % take a look at the first ten rows
ans =
cccb
accc
ccba
babb
cbba
cbaa
bccc
bcbb
babc
cbbc

If you really want the characters "separate" then you could use a cell array:

>> c = num2cell(m);

Answer 3

[Image Analyst]

Looks like you want to put a space between characters. To do that, try this:

% Demo to interleave spaces between letters in a string.
s = 'abcb'  % A simple string as your input.
spaces = ones(length(s), 1) * ' '
s2 = reshape([s', spaces]', 1, [])  % s2 now has spaces after the letters
% If you want to trim off any trailing space, use strtrim()
s2Trimmed = strtrim(s2)