Hello all,

I'm writing a code that generates sine waves, adds random noise, and then cleans it up by averaging those values. I've got it so it averages every 3 values using a sliding point window, however I need to write it as an array and to tell the truth, I'm stumped. I understand what to do...I just can't think of how to implement that in C.

Any help would be greatly appreciated!Code:/* Alexander DeTrano This program generates normal sine waves then creates noise using random numbers and the "cleans up the wave" by a series of averages and then plots them on screen. When N = 40000 a high pitched noise is created intitally and then when the wave with noise is added, a static is picked up, then the averaged values clean it up and reduce some static. */ #include <stdio.h> #include <math.h> #include <stdlib.h> #include <time.h> #define N 40000 double r, pi, f = 1500, w, 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] = sin(w*t); } } void print_array(double y[], int n) { for ( i=0; i<n; ++i ) { printf("%f\n",y[i]); } } void add_noise(double y[], int n) { for( i=0; i<n; ++i) { r = 2*(rand()/(RAND_MAX+1.0)) - 1; t = i/8000.0; y[i]=r + sin(w*t); } } void avgm( double y[], int n, int m) /* this is my old function using constant values for the moving point window. * Basically a0 a1 and a2 need to go inside an array that's size m and have them averaged similar to how they are averaged here */ { double a0=0, a1=0, a2=0; for (i=0;i<n;++i) { a0=a1; a1=a2; a2=y[i]; y[i]=(a0+a1+a2)/3.0; } } int main( void) { int seed; double y[N]; int m; void create_sine(double y[], int n); void print_array(double y[], int n); void add_noise(double y[], int n); void avgm(double y[], int n, int m); pi = 4*atan(1); w = 2*pi*f; seed = time(0); srand(seed); create_sine( y, N); print_array( y, N); add_noise( y, N); print_array( y, N); avgm( y, N, 3); print_array( y, N); return 0; }

Cheers,

Alexander