problems with structure

**pokhara** · 07-08-2009

Code:

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

void read();


int Time, RH, retv;
float DewPointC;
float DryTempC;
float val, val1;
float VPD,vapourp, setvapp; 
char line[256];
FILE *in;
int main()
 {	
	in = fopen("KBIS_2005.txt", "r");
	read();	
	
	return 0;
	calculate();
	return 0;
			
	
}

void read()
{	
	
	int i;

	for(i = 0; i<=240; i++) 
		{
			fgets(line,256,in);
			retv=sscanf(line,"%d %f %f %d",&Time,&DewPointC,&DryTempC,&RH);
			if (!retv) continue;
			printf("%d items read: %d %f %f %d\n",retv,Time,DewPointC,DryTempC,RH);
			val = ((7.5 * DewPointC) / (237.7 + DewPointC));
			vapourp = pow(611, val);
		
			                                                                                                                                                                                                                          
			val1 = ((7.5 * DryTempC)/(237.7 + DryTempC));
			setvapp = pow(611, val1);
	
		
			VPD = setvapp - vapourp;
			printf("VPD IS %f",VPD);
			if(VPD < 0.5)
			{
				printf("value is %d",1);
			}
			else
			{
				printf("val is %d",0);
			}
				
	
	
		}	
	
}

in this code i tried to apply the formula to the first line too..but it is not taking the data from the first line.it is taking from the 1 line but i need from line 0. help me.

**MK27** · 07-08-2009

Here is a problem:

Code:

int main()
 {	
	in = fopen("KBIS_2005.txt", "r");
	read();	
	
	return 0;
	calculate();
	return 0;
			
	
}

An unconditional return statement in main() is the end of the program.

ps. leave your message outside the code brackets!

**pokhara** · 07-08-2009

Code:

void read();


int Time, RH, retv;
float DewPointC;
float DryTempC;
float val, val1;
float VPD,vapourp, setvapp; 
char line[256];
FILE *in;
int main()
 {	
	in = fopen("KBIS_2005.txt", "r");
	read();	
	
	return 0;
	
			
	
}

void read()
{	
	
	int i;
	int store, store1;
	for(i = 0; i<=240; i++) 
		{
			fgets(line,256,in);
			retv=sscanf(line,"%d %f %f %d",&Time,&DewPointC,&DryTempC,&RH);
			if (!retv) continue;
			printf("%d items read: %d %f %f %d\n",retv,Time,DewPointC,DryTempC,RH);
			val = ((7.5 * DewPointC) / (237.7 + DewPointC));
			vapourp = pow(611, val);
		
			                                                                                                                                                                                                                          
			val1 = ((7.5 * DryTempC)/(237.7 + DryTempC));
			setvapp = pow(611, val1);
	
		
			VPD = setvapp - vapourp;
			printf("VPD IS %f",VPD);
}}

my actual code is this..still why it is not taking the first line

**tabstop** · 07-08-2009

But there's no data on line 0, or so you've said. If the first line of the file contains real data, then it will not be skipped.

**pokhara** · 07-08-2009

Code:

"Time"	"DryTempC"	"DewPointC"	"RH"
0	0.6	-5	67
 1	0	-3.9	75
2	0	-3.9	75

this is the file looks like..there is line 0..so i need to read that too..that one is read but while calculating it is not using the first line..it starts calculating after the 0 line...that is frm 1 line...

**pokhara** · 07-08-2009

Code:

if(VPD < 0.5)
			{
				 set = strcpy(store, 1);
				 printf("value is %s",set);
				 //printf("value is %d ",1);
			}
			else
			{	 set1 = strcpy(store1,0);
				 printf("val is %s",set1);
				 //printf("val is %d ",0);
			}

how to use strcpy for integer?is this the way to do?

**MK27** · 07-08-2009

Originally Posted by pokhara

my actual code is this..still why it is not taking the first line

Do you mean it is skipping a line from the file? You could try another printf debugging line here:

Code:

			fgets(line,256,in);
                        printf("%d: %s",i,line);
			retv=sscanf(line,"%d %f %f %d",&Time,&DewPointC,&DryTempC,&RH);
			if (!retv) continue;

printf() is great for debugging, you can cut 'n paste them and change a few things to keep an eye on data. When I have a problem I sometimes end up with them every few lines. Usually what I do is not indent them so they are easy to find and remove when I'm finished*. Also you can temporarily //comment them out.

There is a GUI version of gdb (the gnu debugger, I think you are using linux?) called "ddd" that makes this easier (in a sense...) but don't worry about that right now, I think printf() will do fine.

*which makes the code look very sloppy, temporarily

**tabstop** · 07-08-2009

Originally Posted by pokhara

Code:

"Time"	"DryTempC"	"DewPointC"	"RH"
0	0.6	-5	67
 1	0	-3.9	75
2	0	-3.9	75

this is the file looks like..there is line 0..so i need to read that too..that one is read but while calculating it is not using the first line..it starts calculating after the 0 line...that is frm 1 line...

The code you posted does not do this. The code you posted gives output that starts with:

Code:

4 items read: 0 0.600000 -5.000000 67
VPD IS -0.7731334

**pokhara** · 07-08-2009

i don't want to skip the first line..instead i need to use it too for the calculation. while reading the file the first line is also read but i need to use that line for the calculation too..but why it is not reading the first line.

**pokhara** · 07-08-2009

@MK27..i did that step too but still it is taking from line 1 with time 1..its not taking the time 0 line..
@tabstop...yah it is the giving the same result...so the first line is not read

**tabstop** · 07-08-2009

Originally Posted by pokhara

@tabstop...yah it is the giving the same result...so the first line is not read

Except that .... that is the result from the first line. How can you can claim that the first line is not read when your program is (a) printing it back out and (b) calculating with it?

**MK27** · 07-08-2009

Well, it definitely will read every line, so that extra printf should print every single line. By comparing that to whatever happens next in the output, you should be able to figure out where the problem is.

**pokhara** · 07-08-2009

@MK27..i didnot get u..so u mean that the formula is also reading the first line ..that is line with time 0..as far as i beleive it is taking from the line with time 1...

**brewbuck** · 07-08-2009

Originally Posted by tabstop

It's legal, if bizarre (consecutive strings are merged into one during preprocessing. It reminds me of machine-generated code (like p2c or something), except the variable names make sense. Of course, that's not a style you want to copy as such.

He's sure.

Code:

printf( "Hey now, I happen to think that this particular feature of C preprocessing is very\n"
        "useful and in fact I've used it many time myself when the need arises to embed a\n"
        "long string (such as a banner message) directly into the source code when it is not\n"
        "feasible to store the message in an external file.\n" );

**pokhara** · 07-08-2009

@tabstop...i got that problem solved..it reads the first line too now..thnks
@MK27...i got that problem solved..it reads the first line too now..thnks