Sort row by row cell matrix?

Hello all, I tried to sort a cell matrix, row by row with sortrows function but this sort all matrix instead of each row.

I would like to sort:

a=[{'c'},{'b'},{'a'};
   {'c'},{'a'},{'b'};
   {'c'},{'b'},{'a'};]

With this output:

a=[{'a'},{'b'},{'c'};
   {'a'},{'b'},{'c'};
   {'a'},{'b'},{'c'};]

Could someone help me?

Thank you!!!

[Guillaume]

What a strange way to declare the cell array.

a = {'c', 'b', 'a';
     'c', 'a', 'b';
     'c', 'b', 'a'}

requires less typing. But if all cells are just a single character then using a char array:

a = ['cba'; 'cab'; 'cba']

is even simpler.

[Stephen23]

Why the really strange cell array definition? It is much easier to define a cell array like this:

a = {'c', 'b', 'a'; 'c', 'a', 'b'; 'c', 'b', 'a'}

Answer 1

[the cyclist]

sort(a')'

[the cyclist]

You need to do the awkward transpose-sort-transpose, because the sort command will only sort along the first dimension for a cell array.

[Diego Makasevicius Barbosa]

Hi, I think this solution do not solve this problem, cause when I just sort(a')', it return a 1xn array sorted.

e.g:

 a=[{'c'},{'b'},{'a'};
{'f'},{'d'},{'e'};
{'b'},{'c'},{'a'};]

sort(a')'

Outputs (1x9): 'a' 'a' 'b' 'b' 'c' 'c' 'd' 'e' 'f'

And I want (3x3):

    'a'    'b'    'c'
    'd'    'e'    'f'
    'a'    'b'    'c'

Thank you!!!

[the cyclist]

I get a 3x3 output for that case, as expected. Maybe double-check that the input was really 3x3 when you tested?

[the cyclist]

To be clear, this was the exact code I ran:

a=[{'c'},{'b'},{'a'}; {'f'},{'d'},{'e'}; {'b'},{'c'},{'a'};];
sort(a')'

[the cyclist]

As verified by Image Analyst and myself:

a = {'home', 'apple', 'tiger'; 'onion', 'house', 'knife'; 'sugar', 'money', 'rich'}
sorted_a = sort(a')'

yields, as expected:

a = 
    'home'     'apple'    'tiger'
    'onion'    'house'    'knife'
    'sugar'    'money'    'rich' 

sorted_a = 
    'apple'    'home'     'tiger'
    'house'    'knife'    'onion'
    'money'    'rich'     'sugar'

Answer 2

[Image Analyst]

Perhaps this:

a=[{'c'},{'b'},{'a'};
   {'c'},{'a'},{'b'};
   {'c'},{'b'},{'a'};]

charArray = cell2mat(a)
% Sort each row individually
for row = 1 : size(charArray, 1);
  [~, sortOrder] = sort(charArray(row, :));
  charArray(row,:) = charArray(row, sortOrder);
end
% Print to command window
charArray

The end is a character array, which is a heck of a lot easier to deal with than a cell array.

[Diego Makasevicius Barbosa]

Thank you Image Analyst! I programmed this way actually, but I would like to know if you have a simpler solution, without requiring the use of a loop.

[Image Analyst]

Guillaume has given two one-liners - one for cell arrays and one for character arrays. I suggest you avoid cell arrays unless you really need them (like for mixed data types or strings that are not all the same length), and in this situation you don't need cell arrays at all.

Answer 3

[Guillaume]

a = {'c', 'b', 'a';
     'c', 'a', 'b';
     'c', 'b', 'a'}
num2cell(sort(cell2mat(a), 2))

is all that is needed. But as stated, if a was a char array to start with:

a = ['cba'; 'cab'; 'cba'];
sort(a, 2)

is so much simpler.

[Diego Makasevicius Barbosa]

Thank you for the answer Guillaume! But I think your solution does not work if instead of the cells are words (my case):

eg:

a = {'home', 'apple', 'tiger'; 'onion', 'house', 'knife'; 'sugar', 'money', 'rich'}

[the cyclist]

Can someone besides me please verify that

sort(a')'

does work for this case as well? I'm baffled why Diego can't just use this very simple solution.

[Image Analyst]

Verfied:

a = {'home', 'apple', 'tiger'; 'onion', 'house', 'knife'; 'sugar', 'money', 'rich'}
sorted_a = sort(a')'

a = 
    'home'     'apple'    'tiger'
    'onion'    'house'    'knife'
    'sugar'    'money'    'rich' 
sorted_a = 
    'apple'    'home'     'tiger'
    'house'    'knife'    'onion'
    'money'    'rich'     'sugar'