Unnest a Matrix of strings

I have an older version of matlab (R2008a) and I am trying to Unnest an output from a for loop where the out put should be a 3x3 matrix of strings. Where the output currently displayed is:

M
= {3x1 cell} {3x1 cell} {3x1 cell}

I have tried:

[L{:}]

But this returns a matrix where the cells in the third column are still displayed as:

[1x22 char]
[1x21 char]
[1x29 char]

any help would be appreciated thanks

B-

Answer 1

[Andrew Newell]

If I understand what you're trying to do, you can't do it. A 3x3 matrix of strings looks like this:

['abc';'def';'ghi']

ans =

abc
def
ghi

If you try something like repmat(ans,[1 3]), you get:

ans =

abcabcabc
defdefdef
ghighighi

If you want a string array, you could try

char([L{:}])

This will give you an array of 9 strings, one per line.

EDIT: Based on the discussion below, you might want to try:

fileID = fopen(your_file_name,'r');
C = textscan(fileID,'%s %s %s\n','Delimiter',',');
fclose(fileID)

EDIT2: Based on further discussion, I think this will do what you want:

fileID = fopen('string_data','r');
C = textscan(fileID,'%s %s %s\n','Delimiter',',','CollectOutput',true);
fclose(fileID);
C = regexprep(C{1},'''','')

The textscan command divides the strings up, ignoring the commas, and collects the result in a cell array C inside of which is an N x 3 cell array (don't you just love MATLAB I/O?). The regexprep command gets rid of stray quotation marks.

Answer 2

[Ced]

I'm afraid that this is a bit unavoidable.

L = [M{:}];

would return you a 3x3 cell with the desired strings. If you convert that into a matrix though (e.g. with cell2mat), you run into two problems:

a) [ 'ab','bb','cb' ] is interpreted by matlab as a concatenation of characters, and not three distinct entries of a matrix.

b) if I understand correctly, your entries do not all have the same number of characters. Because matlab interprets each character of a string as a "column" in a matrix, you cannot save strings of different lengths in the same matrix.

Personally, I would go with a 3x3 cell. I don't see a reason not to use cells for non-numerical values.

EDIT: too slow... :)

[Brian Morrison]

I appreciate the quick responses.

I apologize if I wasn't clear enough. (first time poster) I simplified the problem to ask a more concise question.

What I am really trying to do is reorganize a large file for work. This can probably be done in excel but I am not at all familiar at excel as I am with Matlab.

I am starting with about 8000 lines like so:

'abc, defg, hijkl'

'mnop, qrs, tuv'

'wxyz, ab, cdef'

. . .

I want to end up with a 3 column matrix (or cell, no sure what the correct terminology is)(if it is possible):

M=
{'abc' defg' hijkl'

 'mnop' 'qrs' 'tuv'

 'wxyz' 'ab' 'cdef'

                 ...}

I know how to "break up" each line with something like a strsplit function and then I can even group 'abc,'mnop', and 'wxyz'. But ran into the issue where I got an output like the matrix below when I tried to regroup each column of data to form one matrix instead of three separate arrays:

M= {'abc' defg' [1x22 char]

    'mnop' 'qrs' [1x21 char]

      'wxyz' 'ab' [1x29 char]

                            ...}

any further pointers would be greatly appreciated.

[Andrew Newell]

I'm not sure what you mean by regrouping each column of data. What command did you use and what do you want to see in the final version of M?

[Andrew Newell]

Also, do the strings in your file actually have quotes around them, or do they look like this?

abc, defg, hijkl

[Brian Morrison]

They have the quotes.

When I say "regroup" I mean I took 'abc', 'mnop', 'wxyz', and made that a 1x3 matirx and called it "A".

Then I took 'defg', 'qrs', and 'ab', made that a 1x3 matrix and called it "B"

Then I took 'hijkl', 'tuv', and 'cdef' made that a 1x3 matrix and called it "C"

I then wrote M=[A,B,C] and got the result

M=  'abc'       'defg'      [1x22 char]

     'mnop'       'qrs'       [1x21 char]

     'wxyz'        'ab'       [1x29 char]

[Andrew Newell]

I think I understand what you want now, and my second edit in my own answer will do it.

Answer 3

[Konstantinos Sofos]

Hi,

You could use simple the vertcat

vertcat(M{:})

Example:

>> M = {{'a','b','c'},{'d','e','f'},{'g','h','I'}}

M = 

      {1x3 cell}    {1x3 cell}    {1x3 cell}

>> L = vertcat(M{:})

L = 

      'a'    'b'    'c'
      'd'    'e'    'f'
      'g'    'h'    'I'

Regards,