Thread: Array Problem

Hi I'm having some problems with this code. This program generates sine waves and inputs the value into an array. Originally, I had it so it was like void create_sine(double y[], int N) but that gave me this error (which is why I had to use the lower case n, but why it works I do not understand and I'm sure my prof. does not want it like that.)

10 expected `,' or `...' before numeric constant

now I'm getting these errors and I'm stumped.

p1.c:7: warning: initializer element is not constant
p1.c:7: warning: (near initialization for 'pi')
p1.c:7: error: initializer element is not constant
p1.c: In function 'main':
p1.c:28: warning: ISO C90 forbids variable-size array 'y'

Any help would be appreciated!

Code:

#include <stdio.h>
  #include <math.h>
  #include <stdlib.h>
  #include <time.h>
   
  #define N 100
  double r, pi = 4*atan(1), f = 1500, w = 2*pi*f, t ; 
  int i; int n=N;
  
  void create_sine(double y[], int n)
{
     for( i = 0; i < N; ++i)
     {
          t = i/8000.0;
       y[i] = r + sin(w*t);
       }
}
void print_array(double y[], int n)
{
     for (i=0; i<N; ++i)
    {
        printf("%f\n",y[i]);
        }
}
     
  int main( void)
  {
    int seed; double y[n];
    void create_sine(double y[], int n);
    void print_array(double y[], int n);
    
   
    seed = time(0);
   
    srand(seed);
    create_sine( y, N);  
    print_array( y, N);
    
   
    return 0;
  }

Sweeeet! thank you very much!