Constant Y Value, large number of points

TeeChart for ActiveX, COM and ASP
Post Reply
nbp
Newbie
Newbie
Posts: 83
Joined: Mon Sep 18, 2006 12:00 am

Constant Y Value, large number of points

Post by nbp » Fri Apr 25, 2008 7:23 pm

I have a line (X/Y) series plot with several thousand data values. They all have the same Y value but differ in X. I should see a straight horizontal line, but instead I see series values all over the place. The Y axis is labelled with the correct Y-value with Y Minimum and Y Maximum being the same. All the labels on the Y-Axis are labelled the same (correct Y value). Is this a bug? Should I be setting some atribute of the chart so as the get the correct display?

When I change the Y Minimum and Maximum manually so that the correct (constant) Y value falls between the min and max, I see the data displayed correctly as a straight horizontal line.

Yeray
Site Admin
Site Admin
Posts: 9540
Joined: Tue Dec 05, 2006 12:00 am
Location: Girona, Catalonia
Contact:

Post by Yeray » Mon Apr 28, 2008 8:20 am

Hi nbp,

I haven't been able to reproduce the problem here with v8.0.0.3. Please, could you send us a simple example project we can run "as-is" to reproduce it here?
You can either post your files at news://www.steema.net/steema.public.attachments newsgroup or at our upload page.

And also, could you please tell us what exactly TeeChart version are you using?
Best Regards,
ImageYeray Alonso
Development & Support
Steema Software
Av. Montilivi 33, 17003 Girona, Catalonia (SP)
Image Image Image Image Image Image Please read our Bug Fixing Policy

Andrew FT
Newbie
Newbie
Posts: 32
Joined: Thu Mar 31, 2005 5:00 am
Location: Toronto, Canada

Post by Andrew FT » Mon Apr 28, 2008 1:57 pm

Quick suggestion from a passer-by: maybe the values are not exactly the same and you are seeing quantization noise? Are the values mathematically equal or just really close? Try increasing the number of digits on the Y-scale - it might make it obvious what is going on. From my experience, if all your values are exactly the same, TeeChart does not show a min and a max for that axis - it shows a single number in the middle of the scale.

nbp
Newbie
Newbie
Posts: 83
Joined: Mon Sep 18, 2006 12:00 am

Post by nbp » Mon Apr 28, 2008 3:57 pm

Thanks! That's exactly what it was. I changed the number of decimal points on the Y-Axis and realized there were very small differences in the values.

Yeray
Site Admin
Site Admin
Posts: 9540
Joined: Tue Dec 05, 2006 12:00 am
Location: Girona, Catalonia
Contact:

Post by Yeray » Tue Apr 29, 2008 7:42 am

Hi nbp,

I'm glad to read that you solved it!
Best Regards,
ImageYeray Alonso
Development & Support
Steema Software
Av. Montilivi 33, 17003 Girona, Catalonia (SP)
Image Image Image Image Image Image Please read our Bug Fixing Policy

Post Reply