static double some_calc(int arr[], int len) { int index = 0; double foo_1 = 1, foo_2 = 1; while (index

Describe what the following code is doing/calculating:

Extracted text: static double some_calc(int arr[], int len) { int index = 0; double foo_1 = 1, foo_2 = 1; while (index <= len)="" {="" foo_1="" foo_2="foo_2" *="" arr[index]="" *="" index;="" %3d="" foo_1="" +="" foo_1="" *="" arr[index]="" *="" index;="" index++;="" }="" return="" foo_1="">