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javaalgorithmmathpercentagecalculus

Calculate percentage for list of numbers

I have a list of integer values (positive, and negative). I need to calculate the percentage of each value. Is there any API in Java to achieve this?

Example 1 -

10, 40, 60, -15, -25, 30, -10, -50, 120

-50 (lowest value) - 0% -25 - ? -15 - ? -10 - ? 10 - ? 120 (highest value) - 100%

Example 2 -

90, 45, 13, -89, -95, -150, 200, 250, 67

-150 (lowest value) - 0% -95 - ? -89 - ? 13 - ? 250 (highest value) - 100%

Solution

  • I'm not sure if you are asking for normalizing based on the index after sorting or the value. But I think based on value makes more sense. For example if your array is 0, 1, 10, the final percentages will be 0->0%, 1->10%, 10->100%

    For this, you will basically do a normalization.

    I don't remember the exact syntax but correct it if any syntax is wrong. 

    int arr[] = {10, 40, 60, -15, -25, 30, -10, -50};

List b = Arrays.asList(ArrayUtils.toObject(arr));

int mn = Collections.min(b);
int mx = Collections.max(b);

int perc_arr = new int[arr.length];
for(int i = 0; i < arr.length; i++)
     perc_arr[i] = (arr[i]-mn)/(mx-mn)*100;