increasing precison using fprintf for text file

cellArray =

    [ 334]    [38.141794059793398]    [31.983184186130529]    [1.751451095529832e+03]
    [ 352]    [38.094455446389709]    [31.940682658186898]    [1.779530219110660e+03]
    [ 404]    [38.162956465159276]    [32.019563510560964]    [1.542875077314675e+03]
    [ 414]    [38.176654734516106]    [32.068817577008474]    [1.389497182917781e+03]
    [ 476]    [38.075635175382899]    [32.027977260576755]    [1.994276513063349e+03]
    [2729]    [38.229399882994215]    [31.934421897750756]    [1.167495300253853e+03]
    [2730]    [38.205404821919039]    [31.911611428797361]    [1.291408437962644e+03]
    [2742]    [38.104502101643973]    [31.931891003528762]    [1.774978352412581e+03]

 Name           Size            Bytes  Class     Attributes

 cellArray      8x4              3840  cell      global

% I use below codes to write cellArray into txt file

startingFolder='C:\Program Files\MATLAB';
 if ~exist(startingFolder, 'dir');
    startingFolder = pwd;
 end
 defaultFileName=fullfile(startingFolder, '*.txt');
 [baseFileName, folder]=uiputfile(defaultFileName, 'Select a file');
  if baseFileName == 0
    return
  end
  fullFileName = fullfile(folder, baseFileName);  
  c=cellfun(@num2str,cellArray,'un',0);
   [n,m]=size(c);
form=[repmat('%s   ',1,m) ' \r\n'];
fid = fopen(fullFileName, 'w');
for k=1:n
  fprintf(fid, form, c{k,:});
end
fclose(fid);

% but data (2-3-4rd columns) are written only 4 numbers after the comma (like, 38.1418). I need to write the data into txt file without rounding.

[per isakson]

Doc on num2str says

Specify Formatting
Specify the width, precision, and other formatting for an array of 
floating-point values.

    A = gallery('uniformdata',[2,3],0) * 9999;
    s = num2str(A,'%10.5e\n')

[sermet]

I see but how can I apply this for cellfun?

[per isakson]

Replace

    @num2str

by

    @(str) num2str( str, format_specifier )

or better

    >> cellfun( @num2str, {123,34567/3}, {'%d','%18.12f'}, 'uni', false )
    ans = 
        '123'    '11522.333333333334'

Answer 1

[Star Strider]

If you need full precision on all numeric variables and want to use repmat to create your ‘form’ format descriptors, instead of %s, I would use %23.15E. That will print all of them out to full precision.

[sermet]

I tried %23.15E instead of %s but all numeric numbers were converted irrelevant numbers.

[Star Strider]

I don’t know what you mean by ‘irrelevant’. If you want to print your cell array as you posted it, use:

form = '%5d  %23.15E  %23.15E  %23.15E\n'

[sermet]

when I write form as you wrote instead of form=[repmat('%s ',1,m) ' \r\n']; and when the other codes are same, numbers in the text file look like 5.2E+1, 52 4.8E+1 which are irrelevant the above cellarray data.

Is there a more easy way to write cellArray into text file without rounding?

[Star Strider]

I would experiment with the ‘form’ string I suggested in my previous Comment.

[sermet]

Strider, put in a nutshell. I'm sorry but I couldn't get it. Could you write the full codes you're suggesting into the above codes (in header). I'm sorry for the inconvenience.

[Star Strider]

No worries.

The only change I suggested is to use this assignment for ‘form’:

form = '%5d  %23.15E  %23.15E  %23.15E\n';

Experiment with it to see if it works to your satisfaction.

[sermet]

c=cellfun(@num2str,cellArray,'un',0);
     [n,m]=size(c);
  form = '%5d  %23.15E  %23.15E  %23.15E\n'
    fid = fopen(fullFileName, 'w');
  for k=1:n
    fprintf(fid, form, c{k,:});
  end
  fclose(fid);

%when I apply these codes as you suggested (if I got it correct), it produces the attached text file.