public double[][][] getGridDydx1(){
            double[][][] ret = new double[this.lPoints][this.mPoints][this.nPoints];
            for(int i=0; i<this.lPoints; i++){
                for(int j=0; j<this.mPoints; j++){
                    for(int k=0; k<this.nPoints; k++){
                        ret[this.x1indices[i]][this.x2indices[j]][this.x3indices[k]] = this.dydx1[i][j][k];
                    }
                }
            }
            return ret;
        }