WFA_psychometric_chart.Form_handler.CalculateHumidityEnthalpy C# (CSharp) Method

        private void CalculateHumidityEnthalpy(double xVal, double yVal)
        {
            //now lets move towards printing the relative humidity at that position and dew point and enthalpy also wbt
            //first Relative humidity...
            //first we need to see equation w = 622*phi*pg./(patm-phi*pg);
            /*
             we need to calc phi value given by ycord/30 as the max value is 30..
             * second pg which is calculated by temperature pulled from the text file we need to fist
             * calculate the round up value of x coord to an integer...
             */

            //--this part is not correct yet we need to do this again....

            double phi = 0.00000;
            //double y_axis = yVal;
            //now for pg..
            ArrayList temperature_value = new ArrayList();
            ArrayList pg_value_from_txtfile = new ArrayList();

            //--Copying ref temp and humidity
            temperature_value = t;
            pg_value_from_txtfile = pg;
            double temperature = Math.Round(xVal);
            double corres_pg_value = 0.000000;
            for (int i = 0; i < temperature_value.Count; i++)
            {
                if (temperature == Double.Parse(temperature_value[i].ToString()))
                {
                    corres_pg_value = Double.Parse(pg_value_from_txtfile[i].ToString());

                    break;
                }
            }//close of for

            double patm = 101.325;//this is constant...
                                  // double w = 622*phi*corres_pg_value/(patm-phi*corres_pg_value);
                                  //double w1 = 622*phi*pg/(patm-phi*pg);
            double w = yVal;
            phi = w * patm / (622 * corres_pg_value + w * corres_pg_value);//this phi gives the relative humidty..
            phi = phi * 100;//changing into percent..
                            //now display in label...
            humidityCalculated = phi;//--This is the Relative humidity calculated value

            //now lets calculate the dew point...
            double humidity = phi;
            double temperature1 = xVal;
            double TD = 243.04 * (Math.Log(humidity / 100) + ((17.625 * temperature1) / (243.04 + temperature1))) / (17.625 - Math.Log(humidity / 100) - ((17.625 * temperature1) / (243.04 + temperature1)));
            //now lets print this value..
            //        lb_DP.Text = TD.ToString();

            //now lets move towards enthalpy...

            double Patm = 1013;
            double A = 6.116441;
            double m = 7.591386;
            double Tn = 240.7263;
            double B = 621.9907;

            double Pws = A * Math.Pow(10, (m * TD) / (TD + Tn));

            double X = B * Pws / (Patm - Pws);

            double h = temperature * (1.01 + (0.00189 * X)) + 2.5 * X;
            //now lets display this value ..
            enthalpyCalculated = h;//--this is the enthalpy calculated value
        }