org.openscience.cdk.qsar.descriptors.atomic

Class PartialPiChargeDescriptor

java.lang.Object

org.openscience.cdk.qsar.AbstractAtomicDescriptor

org.openscience.cdk.qsar.descriptors.atomic.PartialPiChargeDescriptor

All Implemented Interfaces:

IAtomicDescriptor, IDescriptor

public class PartialPiChargeDescriptor
extends AbstractAtomicDescriptor

The calculation of pi partial charges in pi-bonded systems of an heavy atom was made by Saller-Gasteiger. It is based on the qualitative concept of resonance and implemented with the Partial Equalization of Pi-Electronegativity (PEPE).

Parameters for this descriptor:

Name	Default	Description
maxIterations	0	Number of maximum iterations

Author:

Miguel Rojas

See Also:

GasteigerPEPEPartialCharges

Dictionary pointer(s):

partialPiCharge in the QSAR.sf.net Descriptors Dictionary [qsar-descriptors:partialPiCharge]

Source code:

master

Belongs to CDK module:

qsaratomic

Created on:

2006-04-15

Constructor Summary

Constructors

Constructor and Description
PartialPiChargeDescriptor() Constructor for the PartialPiChargeDescriptor object

Method Summary

Modifier and Type	Method and Description
DescriptorValue	calculate(IAtom atom, IAtomContainer ac) The method returns apha partial charges assigned to an heavy atom through Gasteiger Marsili It is needed to call the addExplicitHydrogensToSatisfyValency method from the class tools.HydrogenAdder.
String[]	getDescriptorNames() Returns an array of names for each descriptor value calculated.
String[]	getParameterNames() Gets the parameterNames attribute of the PartialPiChargeDescriptor object
Object[]	getParameters() Gets the parameters attribute of the PartialPiChargeDescriptor object
Object	getParameterType(String name) Gets the parameterType attribute of the PartialPiChargeDescriptor object
DescriptorSpecification	getSpecification() Gets the specification attribute of the PartialPiChargeDescriptor object
void	initialise(IChemObjectBuilder builder) Default implementation of initialise allows optional override.
void	setParameters(Object[] params) Sets the parameters attribute of the PartialPiChargeDescriptor object

Methods inherited from class org.openscience.cdk.qsar.AbstractAtomicDescriptor

cacheDescriptorValue, getCachedDescriptorValue, isCachedAtomContainer

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openscience.cdk.qsar.IDescriptor

initialise

Constructor Detail

PartialPiChargeDescriptor

public PartialPiChargeDescriptor()

Constructor for the PartialPiChargeDescriptor object

Method Detail

getSpecification

public DescriptorSpecification getSpecification()

Gets the specification attribute of the PartialPiChargeDescriptor object

Returns:

The specification value

setParameters

public void setParameters(Object[] params)
                   throws CDKException

Sets the parameters attribute of the PartialPiChargeDescriptor object

Parameters:

params - 1:Number of maximum iterations, 2: checking lone pair electrons, 3: number of maximum resonance structures to be searched.

Throws:

CDKException - Description of the Exception

See Also:

IDescriptor.getParameters()

getParameters

public Object[] getParameters()

Gets the parameters attribute of the PartialPiChargeDescriptor object

Returns:

The parameters value

See Also:

IDescriptor.setParameters(java.lang.Object[])

getDescriptorNames

public String[] getDescriptorNames()

Description copied from interface: IDescriptor

Returns an array of names for each descriptor value calculated. Many descriptors return multiple values. In general it is useful for the descriptor to indicate the names for each value. In many cases, these names can be as simple as X1, X2, ..., XN where X is a prefix and 1, 2, ..., N are the indices. On the other hand it is also possible to return other arbitrary names, which should be documented in the Javadocs for the descriptor (e.g., the CPSA descriptor). Note that by default if a descriptor returns a single value (such as ALOGPDescriptor the return array will have a single element

Returns:

An array of descriptor names, equal in length to the number of descriptor calculated..

calculate

public DescriptorValue calculate(IAtom atom,
                                 IAtomContainer ac)

The method returns apha partial charges assigned to an heavy atom through Gasteiger Marsili It is needed to call the addExplicitHydrogensToSatisfyValency method from the class tools.HydrogenAdder. For this method will be only possible if the heavy atom has single bond.

Parameters:

atom - The IAtom for which the DescriptorValue is requested

ac - AtomContainer

Returns:

Value of the alpha partial charge

getParameterNames

public String[] getParameterNames()

Gets the parameterNames attribute of the PartialPiChargeDescriptor object

Returns:

The parameterNames value

getParameterType

public Object getParameterType(String name)

Gets the parameterType attribute of the PartialPiChargeDescriptor object

Parameters:

name - Description of the Parameter

Returns:

The parameterType value

initialise

public void initialise(IChemObjectBuilder builder)

Default implementation of initialise allows optional override.

Specified by:

initialise in interface IDescriptor

Parameters:

builder - chem object build