// Helene Martin, CSE 142
// Prints out temperatures in farenheight and celcius rounded to two digits.

// goal: demonstrates methods that return.
public class ReturnDemo {
	public static void main(String[] args) {
		double nowTemp = 50.6;
		double tomorrowTemp = 72;
		
		double nowTempC = fToC(nowTemp);
		
		System.out.println("It's currently " + nowTemp + "F (" + round2(nowTempC) + "C)");
		System.out.println("Tomorrow, it will be " + tomorrowTemp + 
								 "F (" + round2(fToC(tomorrowTemp)) + "C)");
								 
		System.out.println(round(234.2446442, 3));
	}
	
	// Converts a temperature in farenheight to celcius.
	public static double fToC(double tempF) {
		double tempC = 5.0 / 9.0 * (tempF - 32);
		return tempC;
	}
	
	// Rounds a value to two digits after the decimal point.
	public static double round2(double val) {
		return (double)Math.round(val * 100) / 100;
	}
	
	// Rounds a value to a given number of digits after the decimal point.
	public static double round(double val, int digits) {
		return (double)Math.round(val * Math.pow(10, digits)) / Math.pow(10, digits);
	}
	
	// Calculates the displacement of an object with initial velocity v0 at time t
	// given an acceleration a.
	public static double displacement(double v0, double t, double a) {
		return v0 * t + (a * Math.pow(t, 2)) / 2;
	}
}