org.wallerlab.yoink.adaptive.smooth.smoothfunction.MorokumaSmoothFunction.java Source code

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Here is the source code for org.wallerlab.yoink.adaptive.smooth.smoothfunction.MorokumaSmoothFunction.java

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/*
 * Copyright 2014-2015 the original author or authors.
 *
 * 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 org.wallerlab.yoink.adaptive.smooth.smoothfunction;

import org.springframework.stereotype.Service;
import org.wallerlab.yoink.api.service.adaptive.SmoothFunction;

/**
 * this class is for smooth function used in ONIOM-XS.
 * 
 * @author Min Zheng
 *
 */
@Service("morokumaSmoothFunction")
public class MorokumaSmoothFunction implements SmoothFunction {

    /**
     * this smooth function is used in ONIOM-XS method. for details please see:
     * "ONIOM-XS: An extension of the ONIOM method for molecular simulation in condensed phase"
     * Chemical Physics Letters, Volume 355, Number 3, 2 April 2002, pp.
     * 257-262(6).
     * 
     * @param currentValue
     *            , currentValue(variable) in smooth function
     * @param min
     *            , minimum value in smooth function
     * @param max
     *            , maximum value in smooth function
     * @return smooth factor
     */
    public double evaluate(double currentValue, double min, double max) {
        double smoothFactor;
        if (currentValue > max) {
            smoothFactor = 1;
        } else if (currentValue < min) {
            smoothFactor = 0;
        } else {
            double x = (currentValue - min) / (max - min);
            smoothFactor = 6 * (Math.pow((x - 0.5), 5)) - 5 * (Math.pow((x - 0.5), 3)) + 15.0 / 8 * (x - 0.5) + 0.5;
        }
        return smoothFactor;
    }
}