non-rectangular text file upload

Hi,

I have a text file in the following form:

var1, val
var2, val
var3, val, val, val
var4, val, val
var6, val

so each line represent a variable that can be either a float or a vector of float. I would like to import this data in matlab where I would have a variable named var1 that would contain the values given in the text file, and so forth.

I have looked at various documentations but i cannot find something that work for my case: there should be a same number of column and I cannot figure out how to have that variable name in my matlab code.

Thanks for your help/suggestions! Leo

Answer 1

[Andrew Newell]

This will do it:

fid = fopen('data.csv');
tline = fgetl(fid);
while ischar(tline)
  ind = find(tline==',',1,'first');
  eval([tline(1:ind-1) '= [' tline(ind+1:end),']']);
  tline = fgetl(fid);
end
fclose(fid)

If you don't want to see the output, you can replace the eval line by

   S = evalc([tline(1:ind-1) '= [' tline(ind+1:end),']']);

EDIT: If you wish to follow Walter's advice and put all your variables in a structure, you could do the following:

fid = fopen('data.csv');
S = struct;
tline = fgetl(fid);
while ischar(tline)
  ind = find(tline==',',1,'first');
  S.(tline(1:ind-1)) = str2num(tline(ind+1:end));
  tline = fgetl(fid);
end
fclose(fid);

[Walter Roberson]

No eval! No eval! Use dynamic structure fields!

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

Answer 2

[leo]

Thanks for your help!

I changed it a bit as my file is slightly different, e.g.:

    var1   3.2    3.3
    var2   string1    string2
    var3   124

so here is what i wrote:

fid = fopen('test.txt');
s = struct;
tline = fgetl(fid);
while ischar(tline)
  arr = regexp(tline,'\t+','split'); % split line with delimiter tab and consecutive as one
  ind = length(char(arr(1)));
  if ind > 0 % check for empty lines
      var_name = tline(1:ind);
      val = arr(2:end);
      if not (isempty(str2num(val{1}))) % check if data is numeric
          val = cellfun(@str2num, val); % if numeric convert to double
          s.(var_name) = val;
      else
          s.(var_name) = val; % for string variables keep cell array
      end
  end
  tline = fgetl(fid);
end
fclose(fid);

what do you think? clean?

[Andrew Newell]

Yes. Nice use of regexp - worth a vote!