Centre of the Universe

Before I move on to other stuff, let us talk about right ascension. All angular representations in astronomy use degrees, except for one. This is the right ascension, the longitude component of the equatorial coordinate system, the full detail of which I will cover in more detail later. This value is stored in hours rather than in degrees, so needs a bit of special consideration.

Since hours, minutes and seconds are very similar to degrees, minutes and seconds, the class to handle it is very similar to what we discussed in the previous tutorial. The major difference between the two is that the hours are in the range 0-24 hours, while degrees are in the range 0-360.

To convert hours to degrees, 1 degree = 4 minutes (of time), and was handled in the tutorial covering the basics of time.

using System;

namespace UraniaLib
{
	/// 

	/// Summary description for UraniaHMS.
	/// 
	public class UraniaHMS
	{
		private long glHours;
		private long glMinutes;
		private double gfSeconds;
		private long glSign;

		public UraniaHMS()
		{
		}

		private void setSign(double pfNum)
		{
			if (pfNum < 0)
			{
				glSign = -1;
			}
			else
			{
				glSign = 1;
			}
		}

		public int IsPositive()
		{
			if (glSign == -1)
			{
				return 0;
			}
			else
			{
				return 1;
			}
		}

		public void setHours(long plHours)
		{
			setSign(plHours);
			glHours = Math.Abs(plHours);
		}

		public void setMinutes(long plMinutes)
		{
			if (glHours == 0)
			{
				setSign(plMinutes);
			}

			glMinutes = Math.Abs(plMinutes);
			while (glMinutes >= 60)
			{
				glMinutes = glMinutes - 60;
				glHours = glHours + 1;
			}
		}

		public void setSeconds(double pfSeconds)
		{
			if ((glHours == 0) && (glMinutes == 0))
			{
				setSign(pfSeconds);
			}
			gfSeconds = Math.Abs(pfSeconds);

			while (gfSeconds >= 60)
			{
				gfSeconds = gfSeconds - 60;
				glMinutes = glMinutes + 1;
			}

			while (glMinutes >= 60)
			{
				glMinutes = glMinutes - 60;
				glHours = glHours + 1;
			}
		}

		public void setHMS(long plHours, long plMinutes, double pfSeconds)
		{
			setSign(plHours);
			glHours = Math.Abs(plHours);
			glMinutes = Math.Abs(plMinutes);
			gfSeconds = Math.Abs(pfSeconds);

			while (gfSeconds >= 60)
			{
				gfSeconds = gfSeconds - 60;
				glMinutes = glMinutes + 1;
			}
			while (glMinutes >= 60)
			{
				glMinutes = glMinutes - 60;
				glHours = glHours + 1;
			}
		}

		public void setDec(double pfDec)
		{
			double fTmp;
			setSign(pfDec);

			glHours = (long)Math.Floor(Math.Abs(pfDec));
			fTmp = (Math.Abs(pfDec) - glHours) * 60;
			glMinutes = (long)Math.Floor(fTmp);
			fTmp = (fTmp - glMinutes) * 60;
			gfSeconds = fTmp;
			while (gfSeconds >= 60)
			{
				gfSeconds = gfSeconds - 60;
				glMinutes = glMinutes + 1;
			}
			while (glMinutes >= 60)
			{
				glMinutes = glMinutes - 60;
				glHours = glHours + 1;
			}
		}

		public long getHours()
		{
			return glHours * glSign;
		}

		public long getMinutes()
		{
			if (glHours == 0)
			{
				return glMinutes * glSign;
			}
			else
			{
				return glMinutes;
			}
		}

		public double getSeconds()
		{
			if ((glHours == 0) && (glMinutes == 0))
			{
				return gfSeconds * glSign;
			}
			else
			{
				return gfSeconds;
			}
		}

		public double getDecFormat()
		{
			double fDec;
			fDec = ((double)glHours + (glMinutes / 60.0) + ((gfSeconds / 60.0 / 60.0))) * (double)glSign;
			return fDec;
		}

		public string getString(string sFormat)
		{
			string sTmp;

			sTmp = glHours.ToString("00") + "h " + glMinutes.ToString("00") + "m " + (gfSeconds.ToString(sFormat)) + "s";

			if (glSign == -1)
			{
				sTmp = "-" + sTmp;
			}
			return sTmp;
		}
	}
}

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