Thread: sscanf problem...help please!

I'm having trouble reading a data file's data using sscanf. The format of the data file (called file.txt) looks like this:

NUMBER OF PARAMS 249
TITLE BLOCK
B211W111
444-565AG
FIGURE 3.6-1a
3-46
NORMAL RUN
COWL 20, NORMAL MODE
CONDITION 6.18-1
PARAMS
time 10 90 8.0 3.0 6.0
speed 10 190 9.0 3.0 6.0
height -100 350 9.0 15.0 6.0
time 10 90 8.0 3.0 1.0
distance0 200000 4.0 3.0 1.0
time 10 90 8.0 3.0 1.0
distance 0 200000 4.0 3.0 1.0


My code should skip down to the "PARAMS" section (which it does) and then it is supposed to read the first variable name and store it (in junk), then read the next two fields (min and max) following the variable name. The problem is that it is not storing the min and max correctly.

Thanks in advance!

My code looks like this:

Code:

#include <stdio.h>
#include <string.h>

int main()
{
   FILE *f;
    char junk[20][10], vars[20][10], min[20][10], max[20][10];
    char * pch, * pch1, s[500];
    int i = 0;
    f=fopen("file.txt","r");
    if (!f)
      return 1;
    //find the first variable for min and max data
    while (fgets(s,sizeof(s),f)!=NULL)
    {
	// skip down to the "PARAMS" line
		pch = strstr (s,"PARAMS");
		if(pch != NULL)
		{
		    // find each variable
		    while (fgets(s,sizeof(s),f)!=NULL)
			{
			    pch1 = strstr (s,vars[i]);
			    if(pch1 != NULL)
			    {
				// record each variables min and max data
				printf("variable name = %s\n",vars[i]);
				sscanf( s, "%s %s %s", junk[i], min[i], max[i]);
				printf("min = %s\n",min[i]);
				i++;
			    }
			}
		}
      }
      fclose(f);

      return 0;
}

I fixed that problem. Sorry it was a stupid mistake I should have caught in the first place. I have another problem. What is the best way to read/store data that is in the following format?
var1
var1_data
var2
var2_data
.
.
.
var(n)
var(n)_data

where, var(n)_data is separate data points of integer and real numbers. There can be as many as 2000 data points per var(n). I don't want to store the var(n) because I already have it. I need to store only it's data. Will sscanf do it or is there a better function for this?

> pch1 = strstr (s,vars[i]);
So what sets up vars[i] in the first place?
What are you comparing with?

Sorry about that. I set it up by opening another file with a variable name list such as:

var1 var2 var3 ...var(n). I use sscanf to read each variable name into an array of variable names. I actually use a version that you posted earlier this week and modified it slightly for my need.

1. How can I use sscanf to process numerous lines of numerical (mixed integer and real numbers) data. The # of data points on each line varies and the number of lines vary.
2. How do I count the number of data points for each var?

The format looks like this:

time
9 9.05 9.1 9.15 9.2 9.25 9.3 9.35 9.4 9.45 9.5
9.55 9.6 9.65 9.7 9.75 9.8 9.85
9.9 9.95 10 10.05 10.1 10.15 10.2 10.25 10.3
10.35 10.4 10.45 10.5 10.55 10.6 10.65 10.7 10.75
10.8 10.85 10.9 10.95 11 11.05 11.1 11.15 11.2
11.25 11.3 11.35 11.4 11.45 11.5 11.55 11.6 11.65
11.7 11.75 11.8 11.85 11.9 11.95 12 12.05 12.1
12.15 12.2 12.25 12.3 12.35 12.4
12.45 12.5 12.55 12.6 12.65 12.7 12.75 12.8 12.85 12.9 12.95 13
13.05 13.1 13.15 13.2 13.25 13.3 13.35 13.4 13.45
13.5 13.55 13.6 13.65 13.7 13.75 13.8 13.85 13.9
13.95 14 14.05 14.1 14.15 14.2 14.25 14.3 14.35
14.4 14.45 14.5 14.55
14.6
speed
10.2519 10.2519 10.2519
10.2392 10.2392 10.2392 10.2265 10.2265 10.2265
10.2137 10.2137 10.2009 10.2009 10.1881 10.1881 10.1881 10.1753 10.1753
10.1753 10.1753 10.1753 10.1753 10.1753 10.1625 10.1625 10.1625 10.1497
10.1497
10.1497 10.1368 10.1368 10.1368 10.1239 10.1239 10.1239 10.1239
10.1111 10.1111 10.1111 10.1111 10.0981 10.0981 10.0981 10.0981 10.0852
10.0852 10.0852 10.0852 10.0852
10.0852 10.0723 10.0723 10.0723 10.0723
10.0593 10.0593 10.0593 10.0464 10.0464 10.0464 10.0464
10.0464 10.0204
9.70302
.
.
.
more of the same



Thanks for helping!

This doesn't store anything, but perhaps it will give you some ideas.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int foo(const char *filename);

int main()
{
   foo("file.txt");
   return 0;
}

int foo(const char *filename)
{
   FILE *file = fopen(filename, "r");
   if ( file )
   {
      char line[BUFSIZ];
      int j = 0, reading = 0;
      while ( fgets(line, sizeof line, file) != NULL )
      {
         if ( strncmp(line, "PARAMS", 6) == 0 )
         {
            reading = 1;
         }
         else if ( reading )
         {
            double value;
            int n;
            char field[20], *end, *number = line;
            while ( sscanf(number, "%19s%n", field, &n) == 1 &&
                    (value = strtod(field, &end)), 
                    end != field && (*end == '\n' || *end == '\0') )
            {
               number += n;
               j += printf("%s ", field); /* being chintzy with screen space */
               if ( j > 72 )
               {
                  j = 0;
                  putchar('\n');
               }
            }
         }
      }
      fclose(file);
      return 1;
   }
   else
   {
      perror(filename);
   }
   return 0;
}

Is the NUMBER_OF_PARAMETERS 249 field supposed to help you know the number or parameters so you can malloc that amount?

Dave thanks for your reply. I fixed that problem. See earlier reply. I'm not looking for anyone to write my code for me. I need help figuring out which c lib functions are appropriate to solve the problems described below.

My new problem is reading lines of data (see the most recent example I posted). The lines are all different...meaning the number of data points on each line varies (there could be only one, there could be as many as 15). The data is a mixture of real and integer numbers all separated by spaces, which may not be an issue since I would store them in a character array. Then I need to recognize when the data ends (the data is always ended by another variable followed by it's data.

Thank you for helping!

ok, but will the trailing zeroes cause a problem ?

What I mean is, it will still read 9, it will probably just store it as 9.000 or something of the sort

No the trailing zeros are ok. I also need to be able to detect when the data ends as shown in the example of the data I used. The data needs to be read into an array of variable data for up to 100 variables. So I would need to read it into say var_data[10][100]?

Thanks!

Didn't think so. Now you can do your stuff.

and of course - it is possible to check the token whether it includes '.'

then - decide whether it is integer... It still can be stored as float, but printed with %.0f format or converted to integer during the printing...

Of cause it will require to store the flag isInteger for each value read...
Or - if all value supposed to be positive - values to be pritnted out as integers can be stored as negetives to indicate this flag...

maybe thre are even better solutions... It's upto you to decide what is suffitient for you...

I'm not sure why you feel the need to have such a large array, but it doesn't matter, you're still using it wrong. A two dimensional array is an array of arrays. Thus, if you want just one element of one of those arrays, you have to use both sets of [ ]. Like so:

Code:

var_data[ i ][ j ] = fltread;

That says: "Place fltread in spot j of array i."


Quzah.

What is datapoint?

Do you mean you have to read up to 20 lines; each line can contain up to 1800 numbers?
Do you really need to store them all or just the min/max/avg?