Package com.singularsys.extensions.djep.diffRules

Class PowerDiffRule

java.lang.Object

com.singularsys.extensions.djep.diffRules.PowerDiffRule

All Implemented Interfaces:

DiffRulesI, JepComponent, Serializable

public class PowerDiffRule
extends Object
implements DiffRulesI

Differentiates a power y^z with respect to a variable. If z is a constant number diff(y^z,x) -> z * y^(z-1) If y is a constant number diff(y^z,x) -> y^z * ln(z) * diff(z,x) otherwise diff(y^z,x) -> z * y^(z-1) * diff(y,x) + y^z * ln(z) * diff(z,x)

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
PowerDiffRule(DJep djep, Operator op)

Method Summary

Modifier and Type	Method	Description
Node	differentiate(ASTFunNode node, String var, Node[] children, Node[] dchildren)	Returns the top node of the derivative of this function wrt to variable var.
Object	getEvalue()
JepComponent	getLightWeightInstance()	Gets a light-weight instance suitable for using in multiple threads.
String	getName()	Returns the name of the function.
void	init(Jep djep)	Initialize the component.
void	setEvalue(Object eValue)	Sets the value used to detect if a constant is e, default Math.E
String	toString()	Returns a string representation of the rule.

Methods inherited from class java.lang.Object

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

Constructor Details

PowerDiffRule

public PowerDiffRule(DJep djep,
 Operator op)

Method Details

init

public void init(Jep djep)

Description copied from interface: JepComponent

Initialize the component. This method is called whenever a component is added to Jep. Hence, it allows components to keep track of the other components they may rely on.

Specified by:

init in interface JepComponent

Parameters:

djep - the current Jep instance

getLightWeightInstance

public JepComponent getLightWeightInstance()

Description copied from interface: JepComponent

Gets a light-weight instance suitable for using in multiple threads.

Specified by:

getLightWeightInstance in interface JepComponent

Returns:

either a new instance, null or 'this'.

toString

public String toString()

Description copied from interface: DiffRulesI

Returns a string representation of the rule.

Specified by:

toString in interface DiffRulesI

Overrides:

toString in class Object

getName

public String getName()

Description copied from interface: DiffRulesI

Returns the name of the function. Used as index in hashtable and as way of linking with standard Jep functions. You probably want to specify the in the constructors.

Specified by:

getName in interface DiffRulesI

differentiate

public Node differentiate(ASTFunNode node,
 String var,
 Node[] children,
 Node[] dchildren)
                   throws JepException

Description copied from interface: DiffRulesI

Returns the top node of the derivative of this function wrt to variable var.

Specified by:

differentiate in interface DiffRulesI

Parameters:

var - The name of variable to differentiate wrt to.

children - the arguments of the function

dchildren - the derivatives of each argument of the function.

Returns:

top node of and expression tree for the derivative.

Throws:

JepException

getEvalue

public Object getEvalue()

setEvalue

public void setEvalue(Object eValue)

Sets the value used to detect if a constant is e, default Math.E

Parameters:

eValue - value to use will be tested using values equals method.