ziver/hal
1
1
Fork 0
Code Pull requests Releases Activity

Added some algorithms and moved some files and fixed some comments

Browse source
This commit is contained in:
Ziver Koc 2009-02-26 17:10:57 +00:00
parent 017a27931a
commit 9297bea93d
25 changed files with 1043 additions and 192 deletions
Download patch file Download diff file Expand all files Collapse all files

63
src/zutil/math/ZMath.java
View file

@ -1,5 +1,7 @@
package zutil.math;
import java.math.BigInteger;
/**
* Very Simple math functions
*
@ -8,9 +10,68 @@ package zutil.math;
public class ZMath {
/**
* Calculates the percentige the value has
* Calculates the percentage of the values
*/
public static double percent(int min, int max, int value){
return ((double)(value-min)/(max-min))*100;
}
/**
* Solves the equation: x^2 + px + q = 0
*
* @return the two values of x as an array
*/
public static double[] pqFormula(double p, double q){
double[] ret = new double[2];
double t = (p/2);
ret[0] = Math.sqrt( t*t - q );
ret[1] = -ret[0];
t *= -1;
ret[0] += t;
ret[1] += t;
return ret;
}
/**
* Solves the equation: x^2 + px + q = 0.
* WARNING: This uses only BigInteger, thereby removing the decimals in the calculation
*
* @return the two values of x as an array
*/
public static BigInteger[] pqFormula(BigInteger p, BigInteger q){
BigInteger[] ret = new BigInteger[2];
BigInteger t = p.divide( BigInteger.valueOf(2) );
ret[0] = ZMath.sqrt( t.multiply( t ).subtract( q ) );
ret[1] = ret[0].negate();
t = t.negate();
ret[0] = ret[0].add( t );
ret[1] = ret[1].add( t );
return ret;
}
/**
* Calculates the square root of a big number
*
*/
public static BigInteger sqrt(BigInteger value){
BigInteger op = value;
BigInteger res = BigInteger.ZERO;
BigInteger one = BigInteger.ONE;
while( one.compareTo( op ) < 0 ){
one = one.shiftLeft( 2 );
}
one = one.shiftRight(2);
while( !one.equals( BigInteger.ZERO ) ){
if( op.compareTo( res.add( one ) ) >= 0 ){
op = op.subtract( res.add( one ) );
res = res.add( one.shiftLeft( 1 ) );
}
res = res.shiftRight( 1 );
one = one.shiftRight( 2 );
}
return res;
}
}