[C++知识库]C语言 可以动态改变滑动框内元素数目的滑动平均滤波

#直接上代码

#include <stdio.h>
#include <malloc.h>
typedef unsigned           int uint32_t;

//uint32_t _filterArr[5];
uint32_t SlidingFilter (uint32_t num,uint32_t data){ //num=number of sliding boxes , data =new data will input in boxes
  static uint32_t num_record=0; 
  static uint32_t* filterArr;
  float result=0; 
  uint32_t zeroNum=0;
  if(num==0) return data; //without filting if input error parament
	if(num_record==0)//code for first run
	{
	 filterArr = (uint32_t*)calloc(num , sizeof(uint32_t));
	 num_record=num;
	}
	
	if(num_record!=num)//if num changed
	{
	 filterArr = (uint32_t*)realloc(filterArr , num*sizeof(uint32_t));	//attention for the random value
	 if (num>num_record){
	  for (uint32_t i=num_record;i<num;i++)
	  {
		 *(filterArr+i)=0; //reset the new byte that realloc takes
	  }
	 }
	 num_record=num;//renew the num_record
	}


 for (int i=num-1;i>0;i--) //sliding start
	{
	 *(filterArr+i)=*(filterArr+i-1);
	}
  *filterArr=data;//new data 
  
   for (int i=0;i<num;i++) 
	{
	 printf("filterArr[%d] = %d \n",i, *(filterArr+i));
	} 
  
  for (int i=0;i<num;i++) 
	{
	result += *(filterArr+i);//calculate sum
	 //printf("filterArr[%d] = %d \n",i, *(filterArr+i));
	 if(*(filterArr+i)==0)
	 {
		 zeroNum++;    //get the number of zero elements in the arr 
	 }
	} 
	
	//calculate the average
	result/=(num-zeroNum);//floor division without rounting
	
	return result;
}

int main(void) {
   int arr[15]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
   uint32_t Numb=5;
   
   for(int i=0;i<15;i++){
 
   printf("result = %d \n", SlidingFilter(Numb,*(arr+i)));
   }
   Numb=8;
      for(int i=0;i<15;i++){
 
   printf("result = %d \n", SlidingFilter(Numb,*(arr+i)));
   }
    return 0;
}

输入：参与滑动平均滤波的元素个数，最新的一个需要参与滑动平均滤波的数据
输出：最新计算出的滑动滤波值

利用分配堆内存空间的办法存储历史数据，再利用历史数据求最新的滑动滤波值。
在更改 参与滑动平均滤波的元素个数 时候利用动态内存分配的办法。

平均值直接地板除了没四舍五入。