Importing a CSV file as a nested cell array - is it possible

I'm struggling to find any online help documentation on this . Is it possible to import a csv file derived from MSExcel into Matlab directly as a nested cell array

For example if the CSV file has several rows, each with a set of values such as

23,34,1
23,44,55,72,65
4,86,98,7,12,34,9

I want to import this as a nested cell array such that the main array is of size 3 x 1 and each cell contains the data in the csv file row as nested sub arrays. So cell (1,1)of the main array has a (1x3) subarray from the first row of the CSV. Cell 2 has a (1x5) subarray from the second row and Cell 3 has a (1x7) subarray from the third row of the CSV file.

When I use the standard import data function and select 'cell array' from the options Matlab just creates one large 3x 7 array in this example and puts NaNs in the blanks.

Is it actually possible to do this or do I need to create the nested array as a separate step after importing the CSV file and how do I do that .

Many thanks

Answer 1

[Stephen23]

Here is a simple and neat solution using fileread and regexp:

out = regexp(fileread('temp.txt'),'[\n\r]+','split');
out = cellfun(@(s)sscanf(s,'%f,').', out, 'UniformOutput',false);

which we can check in the command window:

>> out{1}
ans =
    23    34     1
>> out{2}
ans =
    23    44    55    72    65
>> out{3}
ans =
     4    86    98     7    12    34     9

The code was tested using this file:

[AndyT]

Thank You Stephen , this does it and using function combinations I would never have found on my own. Much appreciated

[Stephen23]

My pleasure! Note that it will only work for exactly that file format that you specified in your question: as soon as space characters or letters appear in there it will probably fail :)

Answer 2

[Azzi Abdelmalek]

Import your data, then get ride of nan

[AndyT]

Thank you Azzi, not sure I understand this . If I import and get rid of NaN ( which I do with cellfun) it doesn't create the nested cells with the data in that I require.

Answer 3

[Walter Roberson]

fid = fopen('YourFile.csv', 'rt');
counter = 0;
while true
  inline = fgetl(fid);
  if ~ischar(inline); break; end  %end of file
  counter = counter + 1;
  datacell{counter} = textscan(inline, '%f', 'Delimiter', ',');
end

[AndyT]

Many thanks Walter, this works but seems to create 2 levels of the datacell array . The first is a 1x 1 cell and then that contains the data as another subcell e.g. datacell{1,1} is a 1x 7 cell . So the actual data is held in datacell{1,1}{1,1}.