"""
Moving Average
returns a float so no integer rounding applied

"""

class mAvg():

    def __init__(self, size):
        self.size = size
        self.data = [0] * size
        self.nval = 0
        self.sum = 0
        self.next = 0

    def addVal(self, value):
        # add a new value und return new current avg
        if self.nval < self.size:
            # list is not filled
            self.nval += 1
            self.sum += value
        else:
            # list is filled
            self.sum = self.sum - self.data[self.next] - value
        self.data.[self.next] = value
        self.next += 1
        # if end of list reached, start over from beginning
        if self.next = self.size:
            self.next = 0
        return self.sum / self.nval

    def getAvg(self, points=None):
        if self.nval == 0:
            return None
        # get avg of all collected data
        if not points:
            return self.sum / self.nval
        # get avg of subset
        if points > self.nval:
            return None
        sum = 0
        i = self.next
        p = points
        while p > 0:
            p -= 1
            if i == 0:
                i = self.size - 1
            else:
                i -= 1
            sum += self.data[i]
        return sum / points

    def reset(self):
        self.nval = 0
        self.next = 0
        self.sum = 0