JSci.maths.symbolic
Class Variable

java.lang.Object
  JSci.maths.symbolic.Expression
      JSci.maths.symbolic.Variable

All Implemented Interfaces:

java.io.Serializable, Field.Member, Ring.Member, AbelianGroup.Member, Member

public class Variable
extends Expression

Variables in an Expression.

See Also:

Serialized Form

Constructor Summary

Variable(java.lang.String n, java.lang.Object valueSet)

Method Summary

Expression	differentiate(Variable x) Differentiation of the expression with respect to a variable
boolean	equals(java.lang.Object o)
Expression	evaluate() This method substitutes the variable with the variable values, if non-null; they can be Contants or other Expressions.
protected int	getPriority() Get the priority of the operator described by the expression.
java.lang.Object	getSet()
Member	getValue() Get the value of the variable.
void	setValue(Member o) Set the value of the variable.
java.lang.String	toString()

Methods inherited from class JSci.maths.symbolic.Expression

add, difference, differentiate, divide, divide, inverse, inverse, main, multiply, negate, negative, power, product, product, rise, subtract, sum, sum

Methods inherited from class java.lang.Object

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

Constructor Detail

Variable

public Variable(java.lang.String n,
                java.lang.Object valueSet)

Parameters:

n - the name (symbol) of the variable

valueSet - the set to which the variable values belong, e.g. RealField.getInstance(). Note it is not the Class of the values (odd thing indeed).

Method Detail

setValue

public void setValue(Member o)

Set the value of the variable.

Parameters:

o - the value; can be null to unset the variable

getValue

public Member getValue()

Get the value of the variable.

Returns:

the value of the variable; null if the variable is unset.

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

differentiate

public Expression differentiate(Variable x)

Description copied from class: Expression

Differentiation of the expression with respect to a variable

Specified by:

differentiate in class Expression

Parameters:

x - the variable

evaluate

public Expression evaluate()

Description copied from class: Expression

This method substitutes the variable with the variable values, if non-null; they can be Contants or other Expressions. Simplification is performed.

Specified by:

evaluate in class Expression

Returns:

the evaluated Expression. Can be a Constant.

getPriority

protected int getPriority()

Description copied from class: Expression

Get the priority of the operator described by the expression. This is needed only for allowing toString() to generate the parenthesis when needed.

Specified by:

getPriority in class Expression

Returns:

the priority

getSet

public java.lang.Object getSet()