Package com.singularsys.jep.functions

Class Comparative

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.jep.functions.BinaryFunction

com.singularsys.jep.functions.Comparative

All Implemented Interfaces:

PostfixMathCommandI, Serializable

Direct Known Subclasses:

BigDecRelational, NullSafeEquals

public class Comparative
extends BinaryFunction

Implements the comparative operations <, >, <=, >=, != and ==. The <, >, <=, >= operators only work on Double type, while the != and == operators also work on String and Vector arguments. For other types, care might be needed.

Complex numbers are compared using a tolerance which can be set using setTolerance().

Since:

2.3.0 beta 1 a bit of a rewrite to make sub classing easier, now allows Complex to be compared to Double i.e. 1+0 i == 1., 2.3.0 beta 2 changed the internal lt,gt,le,ge,ne and eq method to return boolean. If this breaks anything use if (lt(obj1,obj2)) inStack.push(Double.valueOf(1)); else inStack.push(Double.valueOf(0));, Jep 4.1 List<Object> are compared for equality and inequality by comparing their elements pairwise, so vectors with positive zero and negative zero are considered equal,

Author:

N Funk and R Morris

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.singularsys.jep.functions.BinaryFunction

BinaryFunction.BiFunctionWithException<T>

Field Summary

Fields

Modifier and Type	Field	Description
static final int	EQ
static final int	GE
static final int	GT
static final int	LE
static final int	LT
static final int	NE

Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand

curNumberOfParameters, description, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor	Description
Comparative(int id_in)	Constructor.
Comparative(int id, double tolerance)

Method Summary

Modifier and Type	Method	Description
boolean	compare(Object param1, Object param2)	Compares the two arguments.
boolean	eq(Object param1, Object param2)
Object	eval(Object l, Object r)	Evaluate the function
boolean	ge(Object param1, Object param2)
String	getDescription()	Return a description of the function from the properties file.
int	getId()	Return the ID of the comparative operator
double	getTolerance()	Returns the tolerance used for comparing complex numbers
boolean	gt(Object param1, Object param2)
boolean	le(Object param1, Object param2)
boolean	lt(Object param1, Object param2)
boolean	ne(Object param1, Object param2)
void	setTolerance(double d)	Sets the tolerance used for comparing complex numbers

Methods inherited from class com.singularsys.jep.functions.BinaryFunction

instanceOf, instanceOf, instanceOf, instanceOf, run

Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand

asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, asType, checkNumberOfParameters, getDescription, getDescriptionWithType, getName, getNumberOfParameters, setCurNumberOfParameters, setDescription, setName, toString, toString

Methods inherited from class java.lang.Object

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

Field Details

LT

public static final int LT

See Also:

• Constant Field Values

GT

public static final int GT

See Also:

• Constant Field Values

LE

public static final int LE

See Also:

• Constant Field Values

GE

public static final int GE

See Also:

• Constant Field Values

NE

public static final int NE

See Also:

• Constant Field Values

EQ

public static final int EQ

See Also:

• Constant Field Values

Constructor Details

Comparative

public Comparative(int id_in)

Constructor. Sets the number of parameters to 2. Initializes the tolerance for comparing Complex values.

Parameters:

id_in - The id of the comparative operator.

Comparative

public Comparative(int id,
 double tolerance)

Parameters:

id - one of LT, GT, LE, GE, EQ, NE

tolerance - tolerance for comparing Complex values

Method Details

getId

public int getId()

Return the ID of the comparative operator

Returns:

the id code

Since:

3.5

eval

public Object eval(Object l,
 Object r)
            throws EvaluationException

Description copied from class: BinaryFunction

Evaluate the function

Specified by:

eval in class BinaryFunction

Parameters:

l - lhs argument

r - rhs argument

Returns:

the results

Throws:

EvaluationException - if the function cannot be evaluated.

compare

public boolean compare(Object param1,
 Object param2)
                throws EvaluationException

Compares the two arguments. Result depend on which comparative option has been selected.

Parameters:

param1 -

param2 -

Returns:

Throws:

EvaluationException

lt

public boolean lt(Object param1,
 Object param2)
           throws EvaluationException

Throws:

EvaluationException

gt

public boolean gt(Object param1,
 Object param2)
           throws EvaluationException

Throws:

EvaluationException

le

public boolean le(Object param1,
 Object param2)
           throws EvaluationException

Throws:

EvaluationException

ge

public boolean ge(Object param1,
 Object param2)
           throws EvaluationException

Throws:

EvaluationException

eq

public boolean eq(Object param1,
 Object param2)
           throws EvaluationException

Throws:

EvaluationException

ne

public boolean ne(Object param1,
 Object param2)
           throws EvaluationException

Throws:

EvaluationException

getTolerance

public double getTolerance()

Returns the tolerance used for comparing complex numbers

Returns:

the tolerance

setTolerance

public void setTolerance(double d)

Sets the tolerance used for comparing complex numbers

Parameters:

d - the tolerance

getDescription

public String getDescription()

Description copied from class: PostfixMathCommand

Return a description of the function from the properties file. The property name is the class name followed by ".description". The property is found using the JepMessages class, which can be configured to add additional properties files. If PostfixMathCommand.setDescription(String) has been called, return the description set by that method instead.

Specified by:

getDescription in interface PostfixMathCommandI

Overrides:

getDescription in class PostfixMathCommand

Returns:

the description of the function