NS.java [src/csip/cosu] Revision: Date:
/*
* $Id$
*
* This file is part of the Cloud Services Integration Platform (CSIP),
* a Model-as-a-Service framework, API and application suite.
*
* 2012-2022, Olaf David and others, OMSLab, Colorado State University.
*
* OMSLab licenses this file to you under the MIT license.
* See the LICENSE file in the project root for more information.
*/
package csip.cosu;
/**
*
* Calculates the efficiency between a test data set and a verification data set
* after Nash & Sutcliffe (1970). The efficiency is described as the proportion
* of the cumulated cubic deviation between both data sets and the cumulated
* cubic deviation between the verification data set and its mean value.
*/
class NS extends ObjFunc {
@Override
public String name() {
return "Nash Sutcliffe";
}
@Override
public double eval(double[] obs, double[] sim, double missing) {
checkArrays(sim, obs);
int pre_size = sim.length;
int steps = pre_size;
double sum_vd = 0;
int size = 0;
for (int i = 0; i < obs.length; i++) {
if (obs[i] > missing) {
sum_vd += obs[i];
size++;
}
}
if (size == 0)
throw new RuntimeException("No valid observed values.");
double mean_vd = sum_vd / size;
/*
* calculating mean pow deviations
*/
double td_vd = 0;
double vd_mean = 0;
for (int i = 0; i < steps; i++) {
if (obs[i] > missing) {
td_vd += (Math.pow(Math.abs(obs[i] - sim[i]), 2.0));
vd_mean += (Math.pow(Math.abs(obs[i] - mean_vd), 2.0));
}
}
if (Double.compare(vd_mean, 0.0) == 0)
throw new RuntimeException("No valid mean values.");
return 1 - (td_vd / vd_mean);
}
@Override
public int direction() {
return 1;
}
@Override
public int optimum() {
return 1;
}
}