Calculate running average in C++

RunningAverage.h

#ifndef _RUNNING_AVERAGE_H
#define _RUNNING_AVERAGE_H

#include <vector>
#include <iostream>
#include <cmath>
using namespace std;

class RunningAverage
{
private:
	double val;
	size_t count;

public:
	RunningAverage()
	{
		this->Reset();
	}

	double Update(double valIn)
	{
		double scaling = 1. / (double)(count + 1);
		val = valIn * scaling + val * (1. - scaling);
		count++;
		return val;
	}

	double Get()
	{
		return val;
	}

	size_t Count()
	{
		return count;
	}

	void Reset()
	{
		val = 0.;
		count = 0;
	}
};

#endif //_RUNNING_AVERAGE_H