Panning with Log Axes can bring negative values

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bertrod
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Panning with Log Axes can bring negative values

Post by bertrod » Fri Jan 04, 2008 4:09 pm

Hello,

If you have an axis with Logarithmic = true and the panning tool activated, you can scroll the chart until the logarithmic axis has negative min and max.

The negative values are not displayed, but this causes some strange behaviour with the labels.

I guess a test should be made in class TChartAxis to avoid having negative values on a logarithmic axis. What do you think ?

Regards

xxxxxx
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Post by xxxxxx » Fri Jan 04, 2008 5:16 pm

Hello!
Unless you are indeed ready to dive into deep details of TeeChart, IMHO it's more simple just to trap OnAllowScroll event and do not allow scrolling logarithmic chart beyond respective domain.
Regards, Alexander
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TeeChart Pro v8.05, Delphi 5 & Turbo Delphi Professional for Win32., Delphi & C++Builder 2009

bertrod
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Post by bertrod » Mon Jan 07, 2008 8:01 am

Excellent idea, I had never used the OnAllowScroll event and didn't think about it.

Works fine, thanks.

Although I still think adding a test in TChartAxis class to avoid logarithmic < 0 would not be a too bad idea :wink:

Narcís
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Post by Narcís » Mon Jan 07, 2008 9:31 am

Hi bertrod,

Ok, I've added your request to our wish-list to be considered for inclusion in future releases.
Best Regards,
Narcís Calvet / Development & Support
Steema Software
Avinguda Montilivi 33, 17003 Girona, Catalonia
Tel: 34 972 218 797
http://www.steema.com
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