Rolling Moving Average in C

rolling_moving_average.c

#ifndef MOVING_AVERAGE_H
#define MOVING_AVERAGE_H

#define ROLLING_AVERAGE_WINDOW 6

// Light Sensor (analogue read) - Moving average
int       maverage_values[ROLLING_AVERAGE_WINDOW] = {0}; // all are zero as a start
int       maverage_current_position  = 0;
long      maverage_current_sum = 0;
int       maverage_sample_length = sizeof(maverage_values) / sizeof(maverage_values[0]);

// From: https://gist.github.com/bmccormack/d12f4bf0c96423d03f82
/*
int movingAvg(int *ptrArrNumbers, long *ptrSum, int pos, int len, int nextNum)
{
  //return movingAvg(maverage_values, &maverage_current_sum, maverage_current_position, maverage_sample_length, current_maverage_reading);

  //Subtract the oldest number from the prev sum, add the new number
  *ptrSum = *ptrSum - ptrArrNumbers[pos] + nextNum;
  //Assign the nextNum to the position in the array
  ptrArrNumbers[pos] = nextNum;
  //return the average
  return *ptrSum / len;
}
*/

// Updated
int RollingmAvg(int newValue)
{
         //Subtract the oldest number from the prev sum, add the new number
        maverage_current_sum = maverage_current_sum - maverage_values[maverage_current_position] + newValue;

        //Assign the newValue to the position in the array
        maverage_values[maverage_current_position] = newValue;

        maverage_current_position++;
        
        if (maverage_current_position >= maverage_sample_length) { // Don't go beyond the size of the array...
            maverage_current_position = 0;
        }
                
        //return the average
        return maverage_current_sum / maverage_sample_length;

}

#endif

It works. Thank you very much!