Strcat giving error

Hi all

I have just written a code which works fine for its purpose but gives error while printing answer(Error in ==> intersection at 24

str=strcat(str,',',strcat(num2str(MMH),',',num2str(MorMH)));)

can somebody explain me why it is so?

Best

fid = fopen(strcat('OUTPUT\','intersection1','.csv'), 'w');
for i = 1:length(raw)
    b= raw(i,1);
    if (b==-9999)
                data= raw(i+2:i+21, 1:4);
                y1= data (:,1);
                x1= data (:,2);
                x2= data (:,3);
                x3= data(:,4);
                yn1= transpose (y1);
                xn1= transpose (x1);
                xn2=transpose (x2);
                xn3= transpose (x3);
                P1 = InterX([xn1;yn1],[xn2;yn1]);
                P2 = InterX([xn1;yn1],[xn3;yn1]);

                  MMH= P1(2);
                  MorMH=P2(2);

                    str=strcat(str,',',strcat(num2str(MMH),',',num2str(MorMH)));
                 fprintf(fid, '%s\n', str);

      end
  end
  fclose(fid) ;      
  fprintf('Program Complete');

[Jan]

Please format your code as explained in the "Markup help" link on this page. In addition it is always a good idea to post the complete error message.

[Muhammad]

Thanks Jan

I tried to find the way to manage my code here but could not find it.

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

[Muhammad]

Thanks Roberson.

Answer 1

[Image Analyst]

Why don't you use sprintf() instead? I'm sure it will be much more straightforward. It's virtually identical to fprintf() which you already know how to use.

[Muhammad]

Hi image analyst

Can you please elaborate your answer... how fprintf() may be more useful here?

Thanks

[Jan]

str=sprintf( '%s,%f,%f', str , MMH, MorMH);

[Muhammad]

If there is no fid mentioned in sptintf, how can it then write the output to fid?

[Dr. Seis]

SPRINTF doesn't write out to a file... it is creating a string (in this case called "str" as you have called it above). Then you use this output (i.e., "str") to print out the result using FPRINTF, which is what you did before. This modification was suggested in order to concatenate your string/number information in a way different from (and hopefully more error free than) the way you implemented above. Search for SPRINTF in your help menu (or type "doc sprintf" in the command window) for more information.

Answer 2

[Walter Roberson]

You never initialize str, and you never clear it: your code just keeps growing it longer and printing out the longer and longer string. You need to fix that logic problem before we can suggest what replacement you should use.