Asix scaling is limited

Andre · Post by **Andre** » Thu Apr 07, 2005 5:28 pm

Hello Support,

We are using teechart to show optical signal characterisitcs and recently have found a problem we can't overcome. For optical data, it is natural to use very small values to express characterisitics of optical signal. For example, when we display oscilloscope pattern of signal (time vs power), time is measured in values between [10e-9, 10e-15] which corresponds to picoseconds. But we have disrovered that TeeChart axis does not allow to zoom to interval if interval length is less than 10e-10, actually it is a hardcoded constant in Axis class which prevents zooming. Methods are non-virtual so we cannot override behaviour.

It is critical for us, because this bug is actually a showstopper for project. Could you please motivate why you limit zooming, hint us at workaround or fix as soon as possible.

thank you in advance.

Narcís · Post by **Narcís** » Fri Apr 08, 2005 10:12 am

Hello Andre,

Which version are you using?

Here it works fine using the latest version and the code below.

Code: Select all

		private void Form1_Load(object sender, System.EventArgs e)
		{
			this.line1.Add(1.0e-9);
			this.line1.Add(1.0e-10);
			this.line1.Add(1.0e-11);
			this.line1.Add(1.0e-12);
			this.line1.Add(1.0e-13);
			this.line1.Add(1.0e-14);

			this.tChart1.Axes.Left.Increment = 10.0e-15;
		}

Andre · Post by **Andre** » Fri Apr 08, 2005 2:27 pm

narcis,

I'm using 1.1.1769.19457.
Your code works OK, but try the following:
private void Form1_Load(object sender, System.EventArgs e)
{
this.line1.Add(1.0e-13, 1);
this.line1.Add(2.0e-13, 2);
this.line1.Add(3.0e-13, 4);
this.line1.Add(4.0e-13,

;
}
and do FitToAll, then try to zoom or move series - you will see glitches. The problem is that difference between maximum and minimux values on axis is less than 10e-10

Narcís · Post by **Narcís** » Fri Apr 08, 2005 4:12 pm

Hi Andre,

What do you mean with do FitToAll?

Thanks in advance.

Andre · Post by **Andre** » Mon Apr 11, 2005 12:41 pm

Hi Narcis,

Sorry for not being clear.
I meant that you should do a mouse gesture from right-bottom to left-top so all series data is visible on the chart. After that please try to zoom in, zoom out, mov chart - you will see that zooming works incorrectly.

Narcís · Post by **Narcís** » Mon Apr 11, 2005 1:04 pm

Hi Andre,

Thanks for your reply. Now I've been able to reproduce what you reported. Yes you are right, this strangely doesn't work properly. I've included to our deffect list to be fixed for the next releases.

A workaround could be using greater values than you have (offset the real ones i.e.: 1.0e-10 instead of 1.0e-15) and then on the GetAxisLabel event you could customize the lables so that it displays the correct values.

Andre · Post by **Andre** » Tue Apr 12, 2005 7:23 am

Narcis,

Thanks for workaround. Could you please hint when next maintenance release is scheduled?

Narcís · Post by **Narcís** » Tue Apr 12, 2005 8:08 am

Hi Andre,

By now, the latest release we have thought of is the current one. However TeeChart for .NET v2 BETA is already available from our customer download area for v1 .NET current customers and will be open to the general public in the upcoming days.

Andre · Post by **Andre** » Tue Apr 12, 2005 4:29 pm

Narcis,

Great!
Any chance to get it fixed in the next release (v2 for NET)?

Narcís · Post by **Narcís** » Wed Apr 13, 2005 9:45 am

Hi Andre,

As I told you it already is in our deffect list. We will consider it for inclusion but I can't tell you if it will be.