Class RootUtil

java.lang.Object

edu.jas.root.RootUtil

public class RootUtil
extends Object

Real root utilities. For example real root count.

Field Summary

Fields

Modifier and Type	Field	Description
private static final boolean	debug
private static final org.apache.logging.log4j.Logger	logger

Constructor Summary

Constructors

Constructor	Description
RootUtil()

Method Summary

Modifier and Type	Method	Description
static <C extends RingElem<C> & Rational> Interval<C>	parseInterval(RingFactory<C> fac, String s)	Parse interval for a real root from String.
static <C extends RingElem<C> & Rational> Rectangle<C>	parseRectangle(RingFactory<Complex<C>> fac, String s)	Parse rectangle for a complex root from String.
static <C extends RingElem<C>> long	signVar(List<C> L)	Count changes in sign.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

logger

private static final org.apache.logging.log4j.Logger logger

debug

private static final boolean debug

Constructor Details

RootUtil

public RootUtil()

Method Details

signVar

public static <C extends RingElem<C>> long signVar(List<C> L)

Count changes in sign.

Type Parameters:

C - coefficient type.

Parameters:

L - list of coefficients.

Returns:

number of sign changes in L.

parseInterval

public static <C extends RingElem<C> & Rational>
Interval<C> parseInterval(RingFactory<C> fac,
 String s)

Parse interval for a real root from String.

Parameters:

s - String, syntax: [left, right] or [mid].

Returns:

Interval from s.

parseRectangle

public static <C extends RingElem<C> & Rational>
Rectangle<C> parseRectangle(RingFactory<Complex<C>> fac,
 String s)

Parse rectangle for a complex root from String.

Parameters:

s - String, syntax: [south-west, north-east] or [mid].

Returns:

Interval from s.