edu.cmu.tetrad.calculator.expression.EvaluationExpression Maven / Gradle / Ivy
///////////////////////////////////////////////////////////////////////////////
// For information as to what this class does, see the Javadoc, below. //
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, //
// 2007, 2008, 2009, 2010, 2014, 2015, 2022 by Peter Spirtes, Richard //
// Scheines, Joseph Ramsey, and Clark Glymour. //
// //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation; either version 2 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 General Public License for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program; if not, write to the Free Software //
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA //
///////////////////////////////////////////////////////////////////////////////
package edu.cmu.tetrad.calculator.expression;
import org.apache.commons.math3.distribution.IntegerDistribution;
import org.apache.commons.math3.distribution.RealDistribution;
import java.util.Collections;
import java.util.List;
/**
* An equation expression.
*
* @author Tyler Gibson
*/
public class EvaluationExpression implements Expression {
private static final long serialVersionUID = 23L;
/**
* The variable part of the expression.
*/
private final VariableExpression variable;
/**
* The string you are testing the variable against.
*/
private final String string;
public EvaluationExpression(VariableExpression exp, String s) {
if (exp == null) {
throw new NullPointerException("Variable must not be null.");
}
if (s == null) {
throw new NullPointerException("String must not be null.");
}
this.variable = exp;
this.string = s;
}
public static EvaluationExpression serializableInstance() {
return new EvaluationExpression(VariableExpression.serializableInstance(), "a");
}
public double evaluate(Context context) {
Object o = this.variable.evaluateGeneric(context);
if (o != null && this.string.equals(o.toString())) {
return 1.0;
}
return 0.0;
}
public String getToken() {
return "Eval";
}
public ExpressionDescriptor.Position getPosition() {
return ExpressionDescriptor.Position.NEITHER;
}
public List getExpressions() {
return Collections.singletonList(this.variable);
}
@Override
public RealDistribution getRealDistribution(Context context) {
return null;
}
public IntegerDistribution getIntegerDistribution(Context context) {
return null;
}
}