各位大神，看看这代码干什么用的

using UnityEngine;
using System.Collections;
//过滤器类
public class Filter {
private int num_ = 0;
private float[] filters_ = new float[15];
public Filter(){
for(int i = 0;i<filters_.Length; ++i){
this.filters_[i] = 0.015f;
}
}
public float interval(float d){
this.filters_[num_] = d;
num_++;
if(num_ >= 15)
num_ = 0;
float all = 0;
for(int i =0; i<15; ++i){
all += this.filters_[i];
}
return (all/15);
}
}