how to convert vector char to matrix char ?

I have a variable X = 'ABCDEFGHIJKLMNOPQRSTWXYZ'

how i can fill it in a matrix with single char in single index

like X(1,1)=A ,X(1,2)=B,X(1,3)=C and so on.

[Stephen23]

Using a cell array for this is pointlessly complex and inefficient.

Using a character array, as Chunru shows, is simpler and more efficient.

Answer 1

[Chunru]

You don't need to do anything. X is already an array.

X = 'ABCDEFGHIJKLMNOPQRSTWXYZ' 

X = 'ABCDEFGHIJKLMNOPQRSTWXYZ'

X(2)

ans = 'B'

X(1,2)

ans = 'B'

[yasmeen hadadd]

yes but the new ouput is vector not matrix

[Walter Roberson]

Or at most,

X = 'ABCDEFGHIJKLMNOPQRSTWXYZ';
%then
X = X.'

X = 24×1 char array
    'A'
    'B'
    'C'
    'D'
    'E'
    'F'
    'G'
    'H'
    'I'
    'J'
    'K'
    'L'
    'M'
    'N'
    'O'
    'P'
    'Q'
    'R'
    'S'
    'T'
    'W'
    'X'
    'Y'
    'Z'

[Chunru]

@yasmeen hadadd Vector is a special case of matrix. What matrix do you want to have?

[Walter Roberson]

Examine of copying characters into the matrix.

X = 'ABCDEFGHIJKLMNOPQRSTWXYZ';  %row vector
X(2, [2:end,1]) = X(1,:);
X

X = 2×24 char array
    'ABCDEFGHIJKLMNOPQRSTWXYZ'
    'ZABCDEFGHIJKLMNOPQRSTWXY'

[Walter Roberson]

Note that a single-quoted character literal such as 'ABCD' is considered to be a vector of characters.

clear X
X = 'ABCD';
X

X = 'ABCD'

is the same as

clear X
X(1) = 'A'; X(2) = 'B'; X(3) = 'C'; X(4) = 'D';
X

X = 'ABCD'

This is not just a notation convenience: this is how MATLAB really implements it.

X = 'ABCD'

X = 'ABCD'

double(X)

ans = 1×4

65 66 67 68

The real implementation of X = 'ABCD' is X = uint16([65 66 67 68]) %16 bits per character code followed by marking X internally as being datatype character. It is a numeric vector that is marked to display as character.

... and row vectors are the same thing as 2D arrays in which there just happens to be only 1 row. There is no difference between making X a 2D array of characters that only happens to have one row, compared to making X a row vector of character.

This is different than C. In C, you could have a declaration such as

char X[1][5]

and in C that would be different than

char X[5]

but not in MATLAB. MATLAB just has the equivalent of

struct X {
  uint64 ndims;
  uint64 size*;
  char class[64];
  uint16 flags;
  (void *)data;
}

where data is the pointer to a block of consecutive memory, with there being no individual pointers into rows or columns, with the elements of the array being stored one after the other, but and the array arrangement to be interpreted according to the size field. Rearranging a 1 x 26 array into a 26 x 1 array (through transpose) just involves rewriting the size* contents from [1 26] to [26 1]

Answer 2

[Awais Saeed]

How about using cell?

X = 'ABCDEFGHIJKLMNOPQRSTWXYZ';
v = cellstr(num2cell(X))

v = 1×24 cell array
    {'A'}    {'B'}    {'C'}    {'D'}    {'E'}    {'F'}    {'G'}    {'H'}    {'I'}    {'J'}    {'K'}    {'L'}    {'M'}    {'N'}    {'O'}    {'P'}    {'Q'}    {'R'}    {'S'}    {'T'}    {'W'}    {'X'}    {'Y'}    {'Z'}

By now you use access cells as v{2}, v{4} etc.

v{2}

ans = 'B'

v{3}

ans = 'C'

To make a matrix out of it, you can reshape v as

rows = 4;
vr = reshape(v,rows,[])'

vr = 6×4 cell array
    {'A'}    {'B'}    {'C'}    {'D'}
    {'E'}    {'F'}    {'G'}    {'H'}
    {'I'}    {'J'}    {'K'}    {'L'}
    {'M'}    {'N'}    {'O'}    {'P'}
    {'Q'}    {'R'}    {'S'}    {'T'}
    {'W'}    {'X'}    {'Y'}    {'Z'}

And to access elements from row, for example 2

vr{1,3}

ans = 'C'

[Chunru]

char array is much more efficient than cell array.

X = char('A'+(0:23));
C = reshape(X, [4 6])'

C = 6×4 char array
    'ABCD'
    'EFGH'
    'IJKL'
    'MNOP'
    'QRST'
    'UVWX'

V = cellstr(num2cell(X));
V = reshape(V, 4, [])'

V = 6×4 cell array
    {'A'}    {'B'}    {'C'}    {'D'}
    {'E'}    {'F'}    {'G'}    {'H'}
    {'I'}    {'J'}    {'K'}    {'L'}
    {'M'}    {'N'}    {'O'}    {'P'}
    {'Q'}    {'R'}    {'S'}    {'T'}
    {'U'}    {'V'}    {'W'}    {'X'}

whos    % compare the storage space of C and V

  Name      Size            Bytes  Class    Attributes

  C         6x4                48  char               
  V         6x4              2544  cell               
  X         1x24               48  char