IncPlusPlus/bigtoolbox-math

package io.github.incplusplus.bigtoolbox.math.misc;

import ch.obermuhlner.math.big.BigDecimalMath;

import java.math.BigDecimal;
import java.math.MathContext;

public class MiscUtils
{
    //BEGIN NUMBER MANIPULATION / READING UTILS
    @SuppressWarnings("unused")
    public static int length(int number)
    {
        return (int)(Math.log10(number) + 1);
    }

    @SuppressWarnings("unused")
    public static int length(long number)
    {
        return (int)(Math.log10(number) + 1);
    }

    public static int truncateLeftDigit(int n)
    {
        return n %= Math.pow(10, (int)Math.log10(n));
    }

    public static int truncateRightDigit(int n)
    {
        return n / 10;
    }

    public static int leftDigit(int n)
    {
        return (int)Math.floor(n / Math.pow(10, (int)Math.log10(n)));
    }

    public static int rightDigit(int n)
    {
        return n % 10;
    }

    public static boolean isPalindrome(int in)
    {
        int numberInQuestion = in;
        while(length(numberInQuestion) > 1)
        {
            if(leftDigit(numberInQuestion) != rightDigit(numberInQuestion))
            {
                return false;
            }
            else
            {
                if(length(truncateRightDigit(numberInQuestion)) - length(truncateLeftDigit(numberInQuestion)) != 0)
                {
                    for(int i = 0; i < length(numberInQuestion) - length(truncateLeftDigit(numberInQuestion)); i++)
                    {
                        numberInQuestion = truncateRightDigit(numberInQuestion);
                    }
                    numberInQuestion = truncateLeftDigit(numberInQuestion);
                }
                else
                {
                    numberInQuestion = truncateLeftDigit(numberInQuestion);
                    numberInQuestion = truncateRightDigit(numberInQuestion);
                }
            }
        }
        return true;
    }
    //END NUMBER MANIPULATION / READING UTILS

    //BEGIN VARIOUS ALGEBRA FUNCTIONS
    public static int distance(int x1, int y1, int x2, int y2)
    {
        return distance(new BigDecimal(x1), new BigDecimal(y1), new BigDecimal(x2), new BigDecimal(y2));
    }

    public static int distance(BigDecimal x1, BigDecimal y1, BigDecimal x2, BigDecimal y2)
    {
        return (MiscUtils.sqrt((MiscUtils.pow(x2.subtract(x1), 2)).add(MiscUtils.pow(y2.subtract(y1), 2)))).intValue();
    }
    //END VARIOUS ALGEBRA FUNCTIONS

    //BEGIN EXPERIMENTAL BIGDECIMAL RELATED MATH FUNCTIONS
    //TODO Make a way for the implementing software to specify the MathContext
    private static MathContext mc = MathContext.DECIMAL128;

    /**
     * The following functions are wrapper functions.
     * I made them for the purpose of using easy function names
     * such as sin(x) to work with BigDecimal objects.
     * BigDecimal objects were used to lose as little precision as possible.
     * Use the functions below with caution. They are experimental.
     */

    public static BigDecimal sin(final BigDecimal in)
    {
        return BigDecimalMath.sin(in, mc);
    }

    public static BigDecimal cos(final BigDecimal in)
    {
        return BigDecimalMath.cos(in, mc);
    }

    public static BigDecimal tan(final BigDecimal in)
    {
        return BigDecimalMath.tan(in, mc);
    }

    public static BigDecimal cot(final BigDecimal in)
    {
        return BigDecimalMath.cot(in, mc);
    }

    public static BigDecimal exp(BigDecimal in)
    {
        return BigDecimalMath.exp(in, mc);
    }

    public static BigDecimal pow(BigDecimal in, long exponent)
    {
        return BigDecimalMath.pow(in, new BigDecimal(exponent), mc);
    }

    public static BigDecimal pow(BigDecimal in, BigDecimal exponent)
    {
        return BigDecimalMath.pow(in, exponent, mc);
    }

    public static BigDecimal sqrt(BigDecimal in)
    {
        return nRootBigDecimal(2, in);
    }

    public static BigDecimal cbrt(BigDecimal in)
    {
        return nRootBigDecimal(3, in);
    }

    public static BigDecimal nRootBigDecimal(final int n, BigDecimal in)
    {
        return BigDecimalMath.root(new BigDecimal(n), in, mc);
    }
    //END EXPERIMENTAL BIGDECIMAL RELATED MATH FUNCTIONS
}