adding headers when using fprintf to write to text

Hi,

I am writing a matrix to text using the following codes:

fid = fopen('Datav1Call_1993.txt','w+');

for idx = 1:size(DataPaper,1)
    line = DataPaper(idx,~isnan(DataPaper(idx,:)));  % creates the line of data without NaNs
    fprintf(fid,[repmat('%d ',1,length(line)),'\n'],line);
end

fclose(fid);

how can i add headers to the columns?

[dpb]

Write 'em before the loop after you open the file...result will likely be more satisfactory for looking at if you use widths on the field specifications to line things up...

Answer 1

[Image Analyst]

For example, after fopen() and before the loop:

if fid == -1
    errorMessage = sprintf('Error opening Datav1Call_1993.txt')
    uiwait(errordlg(errorMessage));
    return; % Bail out
end
% Now write header string.
fprintf(fid, 'header 1       header 2       header 3     whatever   \n');

[Danielle Leblance]

when i put

fprintf(fid,'dt ID Year Month Day Obs ROA SigmaROA EqCgta AvgEqCgta ROE0 ...
        ROEM1Q ROEM2Q ROEM3Q ROEM4Q ...
        ROEM1Yr ROEM2Yr ROEM3Yr ROEComp0 ROECompM1Q ROECompM2Q ROECompM3Q ...
        ROECompM4Q ROECompM1Yr ROECompM2Yr ROECompM3Yr TLoans AvgTLoans TA ...
        RELoans CILoans DepLoans ConsLoans AgrLoans FGvLoans LLP ...
        NPL RGL URGL ALLP GTA LCA LCL LC LCnonFAT ...
        LCOff Derivatives ILLoans SLLoans ZScore RWA TedSpread Merger ...
        CreditDev TradingDev size  \n');

I receive an error "Character vector is not terminated properly".

[Walter Roberson]

You cannot continue a string constant with ...

Use

 ['first', 
  'second', 
  'last']

[dpb]

Because you can't continue character constant across line continuation markers...

hdr=['dt ID Year Month Day Obs ROA SigmaROA EqCgta AvgEqCgta ROE0 ' ...
      'ROEM1Q ROEM2Q ROEM3Q ROEM4Q ' ...
      .
      .
      .
      'CreditDev TradingDev size  '];
fprintf(fid,'%s\n',hdr);

NB: Must include the blank between the last substring on the continued line before the first of the following or they'll all run together.

cellstr could be your friend here to make it simpler to code...

[Danielle Leblance]

thanks that was very helpful

[dpb]

>> ['first', 
'second', 
'last'] 
Error using vertcat
Dimensions of matrices being concatenated are not consistent. 
>>

[Image Analyst]

Yes, the triple dots are needed Danielle. With them it's like ['first', 'second', 'last'] which equals 'firstsecondlast', a single 1-d character array. Without them it tries to make a 2D array and for that to succeed, all strings need to be the same length because you can't have a 2-D array with a ragged right edge. However this demo works:

s1 = ['first', ...
'second', ...
'last'] 

s2 = ['first-', 
'second', 
'last--']

You get

s1 =
firstsecondlast
s2 =
first-
second
last--

Note you get a 1-D character array for the first and a 2-D array for the second. I padded the strings so that all strings had 6 characters so now it can make a 3 by 6 character array.