Module ch.bind.philib
Package ch.bind.philib.math

Class Calc

  • public abstract class Calc
extends Object

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected Calc()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static int ceilDiv​(int num, int divisor)
      Divides num by divisor, rounding up if num is not evenly divisible by divisor.
      static long ceilDiv​(long num, long divisor)
      Divides num by divisor, rounding up if num is not evenly divisible by divisor.
      static double clip​(double value, double min, double max)  
      static int clip​(int value, int min, int max)  
      static long clip​(long value, long min, long max)  
      static boolean isAddUnderOrOverflow​(long a, long b, long r)
      Detects under or overflow after calculating result = a + b.
      static long sumOfRange​(long end)
      Calculate the sum of all values from 1 to end, including.
      static long sumOfRange​(long start, long end)
      Calculates the sum of all values from start to end, including.
      static long unsignedAdd​(long a, long b)  

    • Constructor Detail

      • Calc

        protected Calc()

    • Method Detail

      • ceilDiv

        public static long ceilDiv​(long num,
                           long divisor)
        Divides num by divisor, rounding up if num is not evenly divisible by divisor.
        Parameters:
        num - a number >= 0
        divisor - a number > 0
        Returns:
        rounded up num/divisor

      • ceilDiv

        public static int ceilDiv​(int num,
                          int divisor)
        Divides num by divisor, rounding up if num is not evenly divisible by divisor.
        Parameters:
        num - a number >= 0
        divisor - a number > 0
        Returns:
        rounded up num/divisor

      • unsignedAdd

        public static long unsignedAdd​(long a,
                               long b)

      • isAddUnderOrOverflow

        public static boolean isAddUnderOrOverflow​(long a,
                                           long b,
                                           long r)
        Detects under or overflow after calculating result = a + b. Derivation 
         sign bits:
 A B R  Outcome     A^R    B^R   ((A^R) & (B^R))
 0 0 0  OK           0      0           0
 0 0 1  Overflow     1      1           1
 0 1 0  OK           0      1           0
 0 1 1  OK           1      0           0
 1 0 0  OK           1      0           0
 1 0 1  OK           0      1           0
 1 1 0  Underflow    1      1           1
 1 1 1  OK           0      0           0
 ((A^R) & (B^R)) produces a negative number if an under/overflow occurred.
        Parameters:
        a - -
        b - -
        r - result of a + b
        Returns:
        true if an over-, or overflow occurred, false otherwise.

      • sumOfRange

        public static long sumOfRange​(long end)
        Calculate the sum of all values from 1 to end, including. That is: sum = 1 + 2 + 3 + ... + (end-1) + end
        Examples:
        f(0) = 0
        f(1) = 1
        f(2) = 3
        f(3) = 6
        f(10) = 55
        f(100) = 5050
        Parameters:
        end - The end value of the sum-range.
        Returns:
        The sum of all values from 1 to end, including.

      • sumOfRange

        public static long sumOfRange​(long start,
                              long end)
        Calculates the sum of all values from start to end, including.
        Parameters:
        start - The start value of the sum-range.
        end - The end value of the sum-range.
        Returns:
        The sum of all values from start to end , including.

      • clip

        public static int clip​(int value,
                       int min,
                       int max)

      • clip

        public static long clip​(long value,
                        long min,
                        long max)

      • clip

        public static double clip​(double value,
                          double min,
                          double max)