Expert: Joydeep Bhattacharya - 6/21/2007

Question
QUESTION: Hi Joydeep,

I have a small question regarding accessing the text files in C++. Here is what I am writing in C++. Tha algorithm is as follows:
for j = 2:length(image)
{
         Red = image(j,1)+1;
}
where "image" loads/contains a text file and this text file is filled with strings seperated by tab. So how do i write the above algorithm in C++ to achieve the same effect.
As the total text file gets parsed, I need to display the content accordingly i.e. the specified row/columns it is reading.

Any help in this would be appreciated.

Thanks,
Rishi


ANSWER: Hi Rishi

Firstly create a two dimensional array to store the strings in it then open the file

fp = fopen("filename","mode");

read it until you get the end of the file
char x[100][100];
int i=0;
int j=0;
char ch;
FILE fp;

while(feof(fp))
{
 // Now copy a single character using
 ch = fgetc(fp)
 
 if(ch=='\t')
  { x[i][j]='\0'; j++; i=0; } // separated by a tab
 else
  x[i++][j]=ch;   
}

Now you have got all the strings in the two dimensional array x now enjoy ...

In case if you have any problem with the logic please feel free to ask me or you may join me up at http://www.scodz.com also my personal website for more question

regards
Joydeep Bhattacharya
http://www.scodz.com


---------- FOLLOW-UP ----------

QUESTION: Hi joydeep......

Though you could answer my question, still I have a large set of questions and doubt how can I apply above to my part of the code.

I will put down the algorithm that I have written in detail, by which I can put down better understanding. My algorithm is:

Hist = load(fName); /*loads a text file, the text file contains numbers seperated by tab(4 columns)*/
img_3D[][][] = {};//a 3D Array
count = 0;
for j = 2:length(Hist)
         rel_a = Hist(j,1)+1;
         rel_b = Hist(j,2)+1;
         rel_c = Hist(j,3)+1;
         count = imageHist(j,4);
         img_3D(rel_a,rel_b,rel_c) = count;
    end;

I need to write the above algorithm in C++ and stuck on how to proceed.

Any help is really appreciated, as this is my student project.

Please help me write code for this part.

Thanks,
Rishi

Answer
Hi Rishi

I don't have so much time now to write the entire program but would be doing it soon and sending it to you.

What I can understand from your problem is that you want to parse a file and get all the numbers stored there.

I have written a program long back to parse a file containing floats and storing it in a two dimensional array that might prove helpful to you for the time being look at this

http://www.scodz.com/ViewProgram.php?uid=2&link=605

In case of any help please get back to me for the logic and any other stuff required

regards
Joydeep Bhattacharya
http://www.scodz.com