如何将长度为 m 的 Integer 数组转换为 Java 中长度为 n 的数组 [已解决]

Question

Hey want to convert an Integer array from a given length (bigger than 852) to an other Integer array of a lengh of 852.

That's because I want to display m values to 852 pixels.

The logic way is just to devide the ratio betwwen those two:

Let's say the array I want to compress has 2556 values.

The ratio between that is 2556/852 = 3, so I could jsut grab the 3 values and make the average.

The problem is that not allways the ratio is an integer, for example 2756/852 is 3.2347...

Can anyone help me?

Thanks!

Answer 1

I actually solved, I manage to create a function int Java that does exacly what I want. You just need to import import java.util.Arrays;

The function is compressArr(arrayToCompress, newArrayLength)

Returns a float array.

public static float[] compressArr(float[] arr1, int l){
float[] arr2 = new float[l];
for(int i = 0; i<l;i++){
arr2[i] = average(Arrays.copyOfRange(arr1,P1(i,arr1.length,l),P2(i,arr1.length,l)+1));
}
  return arr2;
}

public static int P1(int x,int n, int d){
  float r = ((float)n)/d;
  int b = 0;
  int p = 0;
for(int i = 0; i<x ; i++){
p = (int)(x*r-b);
b*=p;
}
return(p);
}

public static int P2(int x,int n, int d){
  x+=1;
  float r = ((float)n)/d;
  int b = 0;
  int p = 0;
for(int i = 0; i<x ; i++){
p = (int)(x*r-b);
b*=p;
}
return(p-1);
}

static float average(float a[]) {
  int n = a.length;
  float sum = 0;
  for (int i = 0; i < n; i++)
  sum += a[i];
  return sum / n;
}