Hi, first post so please be gentle! basically I'm trying to write a code to do some relativity calculations (yes it's homework, I'm not gonna lie, but i'm stuck) using data from a file. Basically here's the data file:

# Event ID t1 (ns) t2 (ns) E (MeV)

Event: 1 t1 = 91199.24779 t2 = 91209.25718 E = 3087.557027

Event: 2 t1 = 293746.1094 t2 = 293756.1196 E = 91.7881244

Event: 3 t1 = 78354.68253 t2 = 78364.69326 E = 2153.221593

Event: 4 t1 = 141035.6017 t2 = 141045.6123 E = 393.6490052

Event: 5 t1 = 59721.42846 t2 = 59731.43988 E = -155.6911938

Event: 6 t1 = 84348.06297 t2 = 84358.07247 E = 872.6708937

Event: 7 t1 = 30078.92394 t2 = 30088.93519 E = 2082.250327

and here's my code:

For the moment i'm trying to test out my calculations on the first line (where eventid=1), and when that's correct I'll create a function to make it look a little less messy.Code:/* Aarran Shaw 200313078 */ #include <stdio.h> #include <math.h> #include <stdlib.h> int main(void) { FILE *file; char c; int eventid, count=0, negcount=0, count2=0; double t1, t2, energy, total=0.0, time=0.0, average, timeaverage, v, beta, gamma, timetravelled; file=fopen("p3data7.txt","r"); /*file is the input file*/ while ((c=fgetc(file)) != EOF) { if (c=='#') { while (c != '\n') { c=fgetc(file); } } else { ungetc(c,file); /*puts a character back*/ fscanf(file, "Event: %d t1 = %lf t2 = %lf E = %lf \n", &eventid, &t1, &t2, &energy); /*Turns a line of data into variables*/ if (energy>0) { count++; total=total+energy; /*Adds up all the positive energies*/ time=time+t2; /*Adds up all the t2 values associated with the positive energies*/ } else { negcount++; } } } if (count>0) { printf("Number of events with positive Energy ('Good Events') = %d \n",count); printf("Number of events with negative Energy ('Bad Events') = %d \n",negcount); average=total/count; timeaverage=time/count; timetravelled=t2-t1; v=3/((t2*pow(10,-9))-t1*pow(10,-9)); beta=v/299792458; gamma=1/sqrt(1-(beta*beta)); printf("Average Energy = %.2lf MeV \n",average); printf("Average of time t2 = %.2lf ns \n",timeaverage); } else { printf("No positive Energies in the data file, cannot perform calculations. \n"); /*This ensures that if count=0, then it wont divide by zero to return NaN*/ } if (eventid=1) { printf("Velocity=%lf\n",v); printf("beta=%lf\n",beta); printf("gamma=%lf\n",gamma); printf("time=%lfns\n",timetravelled); printf("t1=%lf t2=%lf\n",t1,t2); } fclose(file); return 0; }

Now, I noticed I got the wrong value for gamma, so check all my calculations, hence the if statement at the bottom, and it turns out, that even though i'm asking for the first line (if eventid=1) It's giving me the times t1 and t2 from the final line, hence the velocity v being wrong (gamma should be around 40.5). Could somebody please help me with this? Is the if statement in the wrong place or something?

Any help will be much appreciated, thanks.