How to use cellfun in only cells with numbers or how to create a csv file with different elements (numbers and strings)?

Question

German Preciat Gonzalez 2017-5-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338638-how-to-use-cellfun-in-only-cells-with-numbers-or-how-to-create-a-csv-file-with-different-elements-n

评论： German Preciat Gonzalez 2017-5-4

I have a big cell array (22002x12) with multiple elements (strings and numbers) and I want to convert them to a CSV file but obviously I can't. So I was using cellfun to convert everything in either strings or numbers but is not possible.

So my question is if I have a cell array like this:

 cellArray ={[        1]    '0.431089'      '0.210426'      '0.530389'      '0.529967'      '0.990659';  
             [        2]    '3.63584'       '2.9894'        '2.52868'       '3.80065'       '3.14567';     
             [        3]    [         0]    [         0]    '0.0593239'     [         0]    '0.110771';    
             [        9]    '1.51064'       '1.34827'       '1.77354'       '1.43471'       '1.21254';
             [       10]    '0.080619'      [         0]    '0.0531488'     '0.174925'      '0.0496248';  
             [       12]    '0.129531'      '0.169362'      '0.170763'      '0.21077'       '0.0797323'; 
             [       13]    '0.128055'      '0.133946'      '0.337633'      '0.208367'      '0.118236'}

how could I convert everything into numbers or cells using cellfun (or a better tool)?

I've been using :

matrix = cellfun(@str2num, cellArray)

Or how can I create a CSV file with this data?

I've been using :

csvwrite('new.csv',cellArray)

Thanks in advance!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Stephen23 2017-5-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338638-how-to-use-cellfun-in-only-cells-with-numbers-or-how-to-create-a-csv-file-with-different-elements-n#answer_265581

编辑：Stephen23 2017-5-4

在 MATLAB Online 中打开

This is easy with num2str, which ignores strings. This has the advantage that the output CSV file contains exactly the data in those strings, because there is no loss/rounding/... from converting to numeric and back again.

% Mixed cell array:
C ={[        1]    '0.431089'      '0.210426'      '0.530389'      '0.529967'      '0.990659';  
    [        2]    '3.63584'       '2.9894'        '2.52868'       '3.80065'       '3.14567';     
    [        3]    [         0]    [         0]    '0.0593239'     [         0]    '0.110771';    
    [        9]    '1.51064'       '1.34827'       '1.77354'       '1.43471'       '1.21254';
    [       10]    '0.080619'      [         0]    '0.0531488'     '0.174925'      '0.0496248';  
    [       12]    '0.129531'      '0.169362'      '0.170763'      '0.21077'       '0.0797323'; 
    [       13]    '0.128055'      '0.133946'      '0.337633'      '0.208367'      '0.118236'};
% Cell array of character vectors:
D = cellfun(@num2str,C.','uni',0);
% Save data in CSV file:
fmt = repmat(',%s',1,size(C,2));
fmt = sprintf('%s\n',fmt(2:end));
fid = fopen('temp0.csv','wt');
fprintf(fid,fmt,D{:});
fclose(fid);

and this creates the following CSV file:

1,0.431089,0.210426,0.530389,0.529967,0.990659
2,3.63584,2.9894,2.52868,3.80065,3.14567
3,0,0,0.0593239,0,0.110771
9,1.51064,1.34827,1.77354,1.43471,1.21254
10,0.080619,0,0.0531488,0.174925,0.0496248
12,0.129531,0.169362,0.170763,0.21077,0.0797323
13,0.128055,0.133946,0.337633,0.208367,0.118236

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

German Preciat Gonzalez 2017-5-4

Thanks! exactly what I needed

请先登录，再进行评论。

Answer 2

Andrei Bobrov 2017-5-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338638-how-to-use-cellfun-in-only-cells-with-numbers-or-how-to-create-a-csv-file-with-different-elements-n#answer_265579

编辑：Andrei Bobrov 2017-5-4

在 MATLAB Online 中打开

l0 = cellfun(@ischar,cellArray);
cellArray(l0) = num2cell(str2double(cellArray(l0)));

or

l0 = cellfun(@isnumeric,cellArray);
cellArray(l0) = sprintfc('%d',[cellArray{l0}]);

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 3

Guillaume 2017-5-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338638-how-to-use-cellfun-in-only-cells-with-numbers-or-how-to-create-a-csv-file-with-different-elements-n#answer_265578

在 MATLAB Online 中打开

You would be better off fixing whichever code you've used that creates a mixture of numbers and strings in the same column. You would also be better off using tables instead of cell array.

Failing that:

function x = maybeconvert(x)
   %convert x to number if it is a string, or leave it as is if already number
   if ischar(x)
     x = str2double(x);  %don't use str2num, it's a very dangerous function
end