Im trying to read in some numbers from a file and output the results into another file. Every time I try to do this though I just get random values even for values that I am not modifying. I know it probably has something to do with the way I am reading info but I am not sure. contents of lab4sample.dat
12.4 24.0
5.6 8.0
7.85 12.0
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
//#define FILE_IN “lab4.dat”
#define FILE_IN "lab4sample.dat"
double areaPolygon(double radius, double nsides);
double perimeterPolygon(double radius, double nsides);
int main(void)
{
FILE * infile;
FILE * answer_file;
double radius;
double nsides;
double area;
double perimeter;
infile = fopen(FILE_IN,"r");
if(infile == NULL)
{
printf("Error on opening the data file\n");
exit(EXIT_FAILURE);
}
answer_file = fopen("lab4.out","w");
if(answer_file == NULL)
{
printf("Error on opening the output file\n");
exit(EXIT_FAILURE);
}
fprintf(answer_file, "\n Lab 4.\n\n");
fprintf(answer_file, " Number Perimeter Area Of \n");
fprintf(answer_file, " Radius Of Sides Of Polygon Polygon \n");
fprintf(answer_file, "-------- -------- ------------ ----------- \n");
while((fscanf(infile, "%lf %lf\n",&radius, &nsides))== 2)
{
area = areaPolygon(radius,nsides);
perimeter = perimeterPolygon(radius,nsides);
fprintf(answer_file,"%5.2f %5.2f %5.2f %5.2f \n",&radius,&nsides,&area,&perimeter);
}
}
fprintf(answer_file,"%5.2f %5.2f %5.2f %5.2f \n",&radius,&nsides,&area,&perimeter);
You're printing the addresses of radius
, nsides
, area
, and perimeter
. The &
operator takes the address of a variable. You want to print their values .
You're trying to print a pointer as a floating point number (your compiler should be complaining). Change:
fprintf(answer_file,"%5.2f %5.2f %5.2f %5.2f \n",&radius,&nsides,&area,&perimeter);
To:
fprintf(answer_file,"%5.2f %5.2f %5.2f %5.2f \n", radius, nsides, area, perimeter);
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