public static double pbias(double[] obs, double[] sim) {
        sameArrayLen(obs, sim);
        double sumObs = 0;
        double sumDif = 0;
        for (int i = 0; i < sim.length; i++) {
            sumDif += (sim[i] - obs[i]);
            sumObs += obs[i];
        }
        return (sumDif / sumObs) * 100;
    }
public static double pbias ( double [ ] obs , double [ ] sim ) { sameArrayLen ( obs , sim ) ; double sumObs = 0 ; double sumDif = 0 ; for ( int i = 0 ; i < sim . length ; i ++ ) { sumDif += ( sim [ i ] - obs [ i ] ) ; sumObs += obs [ i ] ; } return ( sumDif / sumObs ) * 100 ; }
@param prediction
@param validation
@return