fan lines placement depends on size of window

Author: haytac

Creation Date: 2/3/2009 10:28 PM

Wealth Lab » WealthScript (.NET) » fan lines placement depends on size of window

haytac

2/3/2009 10:28 PM

I notice that when I draw fan lines, their placement changes as I change the window size. This makes evaluating technical indicators difficult. The origin does not change but the angles change. For example with one size window the 20 day SMA may be above a fan line, with full size window it is below. This problem did not exist with WL4.

It would be great if it were fixed.

Thanks,

Cone

2/4/2009 4:31 AM

I see what you mean, but I also see it somewhat in Version 4 too. Please create a Support Ticket for this one for tracking. tia.

Cone

2/4/2009 12:45 PM

Here's some Gann Fan code to play with. I'll add this to the User Guide -

CODE:
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Color:

Here's some Gann Fan code to play with.  I'll add this to the User Guide -

[CODE]using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using WealthLab;
using WealthLab.Indicators;

namespace WealthLab.Strategies
{
	public class GannFan : WealthScript
	{
		/* Draw a Gann Line and return its value on the last bar of the chart */
		public double DrawGannLine( int bar, double price, int timeUnits, int priceUnits, 
			   						double priceUnitsPerBar, Color color, LineStyle style, bool drawUp)
		{
			//int b2 = bar + (int)Math.Round(timeUnits/priceUnitsPerBar);
			int b2 = bar + timeUnits;
			int bcm1 = Bars.Count - 1;
			double delta = priceUnits * priceUnitsPerBar;
			double y = price + delta;			
			if( !drawUp ) y = price - delta;			
			if( b2 > bcm1 )
			{
				DrawLabel(PricePane, "Sorry, cannot draw this line", Color.Red);
				return -1d;
			}
			else
			{
				DrawLine(PricePane, bar, price, b2, y, color, style, 1);
				double res = LineExtendY(bar, price, b2, y, bcm1);
				DrawLine(PricePane, b2, y, bcm1, res, color, style, 1);
				return res;
			}							
		}
		
		protected override void Execute()
		{			
			/* Draw a Gann Fan from the 9 Oct 2008 low */		
			int tb = DateTimeToBar(new DateTime(2008, 10, 9), false);
			
			/* Adjust the priceToTimeRatio so that the black 45 deg line (1:1) appears to be 45 deg on the chart
			 * If the line is pointing upward too steeply, then raise the value (and vice-versa).
			 */
			double priceToTimeRatio = 0.25;				
			
			if( tb > 0 )
			{
				DrawGannLine( tb, Low[tb], 1, 1, priceToTimeRatio, Color.Black, LineStyle.Solid, true );
				int n = 2;
				do
				{
					if( n < 5 || n == 8 ) {
						DrawGannLine( tb, Low[tb], 1, n, priceToTimeRatio, Color.Blue, LineStyle.Solid, true );
						DrawGannLine( tb, Low[tb], n, 1, priceToTimeRatio, Color.Red, LineStyle.Solid, true );
					}
					n += 1;
				} while (n <= 8);				
			}			
		}
	}
}[/CODE]

haytac

2/5/2009 6:03 AM

Thank you very much!! It would be very helpful to have similar code for 'Draw SpeedResistance lines on the chart' also.

Cone

2/5/2009 6:23 AM

SR line code is already in the User Guide. See the Example at the bottom of the topic.

Incidentally, I just updated the code above (same as in your ticket). It's better (correct) now.