Natour, O. 9/25/15 Csc-111-D01 Hw4

/*
 * Omar Natour
 * 9/25/2015
 * CSC-111-D01
 * Problem: Hw4
 * Calculate temperature, dewpoint, or relative humidity.
 * ojnatour0001@student.stcc.edu
 */

import java.util.Scanner;
import java.lang.Math;

public class WeatherCalc {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        String ans;

        double temp;
        double dew;
        double relh;

        System.out.print("Would you like to calculate Temperature,"
                + " Dewpoint, or Relative Humidity? Enter your choice here:");
        ans = input.nextLine();

        if (ans.equals("Temperature")) {
            System.out.println("You have selected to calculate Temperature.");
            System.out.print("Enter Dewpoint in fahrenheit:");
            dew = input.nextDouble();
            System.out.print("Enter Relative Humidity:");
            relh = input.nextDouble();

            // calculation
            dew = (dew - 32) / 1.8;
            temp = 243.04 * (((17.625 * dew) / (243.04 + dew)) - Math.log((relh / 100)))
                    / (17.625 + Math.log((relh / 100)) - ((17.625 * dew) / (243.04 + dew)));
            temp = temp * 1.8 + 32;

            temp = Math.round(temp * 10.0) / 10.0;

            System.out.println("The temperature is " + temp + "\u00B0F.");

        } else if (ans.equals("Dewpoint")) {
            System.out.println("You have selected to calculate Dewpoint.");
            System.out.print("Enter Temperature in fahrenheit:");
            temp = input.nextDouble();
            System.out.print("Enter Relative Humidity:");
            relh = input.nextDouble();

            // calculation
            temp = (temp - 32) / 1.8;
            dew = 243.04 * (Math.log((relh / 100)) + ((17.625 * temp) / (243.04 + temp)))
                    / (17.625 - Math.log((relh / 100)) - ((17.625 * temp) / (243.04 + temp)));
            dew = dew * 1.8 + 32;

            dew = Math.round(dew * 10.0) / 10.0;

            System.out.println("The Dewpoint is " + dew + "\u00b0F.");

        } else if (ans.equals("Relative Humidity")) {

            System.out.println("You have selected to calculate Relative Humidity.");
            System.out.print("Enter Temperature in fahrenheit:");
            temp = input.nextDouble();
            System.out.print("Enter Dewpoint in fahrenheit:");
            dew = input.nextDouble();

            // calculation
            temp = (temp - 32) / 1.8;
            dew = (dew - 32) / 1.8;

            relh = 100 * (Math.exp(((17.625 * dew) / (243.04 + dew))) / Math.exp(((17.625 * temp) / (243.04 + temp))));
            relh = Math.round(relh * 10.0) / 10.0;

            System.out.println("The Relative Humidity is " + relh + "%.");

        } else
            System.out.print("You have entered an invalid string.");

    }

}