/* $RCSfile$
* $Author: egonw $
* $Date: 2008-05-11 08:06:41 +0200 (Sun, 11 May 2008) $
* $Revision: 10958 $
*
* Copyright (C) 2007 Miguel Rojasch <miguelrojasch@users.sf.net>
*
* Contact: cdk-devel@lists.sourceforge.net
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.openscience.cdk.formula.rules;
import org.openscience.cdk.exception.CDKException;
import org.openscience.cdk.interfaces.IMolecularFormula;
import org.openscience.cdk.tools.ILoggingTool;
import org.openscience.cdk.tools.LoggingToolFactory;
import org.openscience.cdk.tools.manipulator.MolecularFormulaManipulator;
/**
* This class validate if the rule of nitrogen is kept.
* <p>If a compound has an odd number of nitrogen atoms,
* then the molecular ion (the [M]+) will have an odd mass and the value for m/e will be odd.</p>
* <p>If a compound has no nitrogen atom or an even number of nitrogen atoms, then the m/e value of [M]+ will be even.</p>
*
*
* <p>This rule uses these parameters:
* <table border="1">
* <tr>
* <td>Name</td>
* <td>Default</td>
* <td>Description</td>
* </tr>
* <tr>
* <td>charge</td>
* <td>0.0</td>
* <td>The Nitrogen rule of MolecularFormula</td>
* </tr>
* </table>
*
* @cdk.module formula
* @author miguelrojasch
* @cdk.created 2008-06-11
*/
public class NitrogenRule implements IRule{
private static ILoggingTool logger =
LoggingToolFactory.createLoggingTool(NitrogenRule.class);
/**
* Constructor for the NitrogenRule object.
*/
public NitrogenRule() {
}
/**
* Sets the parameters attribute of the NitrogenRule object.
*
* @param params The new parameters value
* @throws CDKException Description of the Exception
*
* @see #getParameters
*/
public void setParameters(Object[] params) throws CDKException {
if (params != null)
throw new CDKException("NitrogenRule doesn't expect parameters");
}
/**
* Gets the parameters attribute of the NitrogenRule object.
*
* @return The parameters value
* @see #setParameters
*/
public Object[] getParameters() {
return null;
}
/**
* Validate the nitrogen rule of this IMolecularFormula.
*
* @param formula Parameter is the IMolecularFormula
* @return A double value meaning 1.0 True, 0.0 False
*/
public double validate(IMolecularFormula formula) throws CDKException {
logger.info("Start validation of ",formula);
double mass = MolecularFormulaManipulator.getTotalMassNumber(formula);
if(mass == 0)
return 0.0;
int numberN = MolecularFormulaManipulator.getElementCount(formula, formula.getBuilder().newElement("N"));
numberN += getOthers(formula);
if(formula.getCharge() == null || formula.getCharge() == 0 || !isOdd(Math.abs(formula.getCharge()))){
if(isOdd(mass) && isOdd(numberN)) {
return 1.0;
} else if(!isOdd(mass) && ( numberN == 0 || !isOdd(numberN))){
return 1.0;
} else
return 0.0;
}else{
if(!isOdd(mass) && isOdd(numberN)) {
return 1.0;
} else if(isOdd(mass) && ( numberN == 0 || !isOdd(numberN))){
return 1.0;
} else
return 0.0;
}
}
/**
* Get the number of other elements which affect to the calculation of the nominal mass.
* For example Fe, Co, Hg, Pt, As.
*
* @param formula The IMolecularFormula to analyze
* @return Number of elements
*/
private int getOthers(IMolecularFormula formula) {
int number = 0;
String[] elements = {"Co","Hg","Pt","As"};
for(int i = 0 ; i < elements.length; i++)
number += MolecularFormulaManipulator.getElementCount(formula, formula.getBuilder().newElement(elements[i]));
return number;
}
/**
* Determine if a integer is odd.
*
* @param value The value to analyze
* @return True, if the integer is odd
*/
private boolean isOdd(double value) {
if(value % 2 == 0)
return false;
else
return true;
}
}