/*
* JaamSim Discrete Event Simulation
* Copyright (C) 2013 Ausenco Engineering Canada Inc.
* Copyright (C) 2016 JaamSim Software Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.jaamsim.CalculationObjects;
import com.jaamsim.Samples.SampleConstant;
import com.jaamsim.Samples.SampleInput;
import com.jaamsim.input.Keyword;
import com.jaamsim.units.DimensionlessUnit;
import com.jaamsim.units.TimeUnit;
import com.jaamsim.units.Unit;
import com.jaamsim.units.UserSpecifiedUnit;
/**
* The Integrator returns the integral of the input values.
* @author Harry King
*
*/
public class Integrator extends DoubleCalculation {
@Keyword(description = "The initial value for the integral at time = 0.",
exampleList = {"5.5 m/s", "[InputValue1].Value"})
private final SampleInput initialValue;
{
initialValue = new SampleInput("InitialValue", "Key Inputs", new SampleConstant(0.0));
initialValue.setEntity(this);
initialValue.setUnitType(UserSpecifiedUnit.class);
this.addInput(initialValue);
}
public Integrator() {}
@Override
protected void setUnitType(Class<? extends Unit> ut) {
super.setUnitType(ut);
outUnitType = Unit.getMultUnitType(ut, TimeUnit.class);
if (outUnitType == null)
outUnitType = DimensionlessUnit.class;
initialValue.setUnitType(outUnitType);
}
@Override
public double getInitialValue() {
return initialValue.getValue().getNextSample(getSimTime());
}
@Override
protected double calculateValue(double simTime, double inputVal, double lastTime, double lastInputVal, double lastVal) {
// Calculate the elapsed time
double dt = simTime - lastTime;
if (dt <= 0.0)
return lastVal;
// Calculate the integral
return lastVal + 0.5*(lastInputVal + inputVal)*dt;
}
}