MATLAB: Removing specific characters from string in nested cells

cellsMATLABnested cellsregexpstring

I have a series of strings which are contained within a nested cell array (because regexp loves to nest cells), and I would like to remove any non numeric or white space characters from them so that I can convert them to doubles, namely astrick.
I'm looking for the least painful way of removing any of these special characters from all strings. I do not have a sample file to attach, sorry, but I have dictated the shape of a sample array below.
X == 1x1 cell
X{1} == 1x1 cell (because regexp can't help itself apparently)
X{1}{1} = {'1234.,  ';'12.,*  ';'1234.,  ','123.,*   ','  321.,*  '};

Best Answer

Perhaps this can easily be achieved in two steps. For your input:
    1  ****TABLE1****
   COLUMN1= 1.12, 2.23, 3.34, 4.45, 5.56, 6.67,
   COLUMN2= 0.00, 0.00, 0.00, 0.00, 0.00, 0.00,
   COLUMN3= 1.23, 0.34, 3.45, 5.78*, 6.54*, 8.23,
   1  ****TABLE2****
Step 1. Find and replace all punctuation characters (let's say ",", "." and "*"). Live regex here .
   data = fileread('CORR.txt');
   expression_sub = '(?<=\d\.\d*\*?)([\*\.,])';
   data = regexprep(data,expression_sub,'');
Data will now not contain those characters. Data is now:
     '   1  ****TABLE1****
        COLUMN1= 1.12 2.23 3.34 4.45 5.56 6.67
        COLUMN2= 0.00 0.00 0.00 0.00 0.00 0.00
        COLUMN3= 1.23 0.34 3.45 5.78 6.54 8.23
        1  ****TABLE2****
     '
Step 2. Match your data. Live regex here. The expression is greedy and will try to match as many digit, full stop, digits combinations as it can. Therefore you don't need to repmat your expression like you showed.
 expression_match = '(?<=COLUMN[1,3]=\s)(\d.?\d*\s)*';
 [tokens,match] = regexp(data_sub,expression_match,'tokens','match');
Matlab manipulation.
 column1 = str2double(strsplit(cell2mat(tokens{1}),' '));
 column3 = str2double(strsplit(cell2mat(tokens{2}),' '));
column1 =
    1.1200    2.2300    3.3400    4.4500    5.5600    6.6700
column3 =
    1.2300    0.3400    3.4500    5.7800    6.5400    8.2300
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