package uk.ac.cranfield.thesis.server.service;
import java.util.ArrayList;
import java.util.List;
import uk.ac.cranfield.thesis.client.service.EquationsService;
import uk.ac.cranfield.thesis.shared.model.Equation;
import uk.ac.cranfield.thesis.shared.model.Solution;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import de.congrace.exp4j.Calculable;
import de.congrace.exp4j.ExpressionBuilder;
import de.congrace.exp4j.UnknownFunctionException;
import de.congrace.exp4j.UnparsableExpressionException;
@SuppressWarnings("serial")
public class EquationServiceImpl extends RemoteServiceServlet implements EquationsService
{
// private ScriptEngine engine = new ScriptEngineManager().getEngineByName("JavaScript");
@Override
public Solution evaluate(Equation equation, List<Double> points) throws UnknownFunctionException,
UnparsableExpressionException
{
if (equation == null)
return null;
List<Double> results = new ArrayList<Double>();
for (Double p : points)
{
Calculable calc = new ExpressionBuilder(equation.getEquation()).withVariable(
String.valueOf(equation.getIndependentVariable()), p).build();
results.add(calc.calculate());
}
return new Solution(results, 0, 10, 1);
}
}