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Bug 181 - [TV52014570] When zooming or scrolling on a graph with logaritmic scales for the b...
Summary: [TV52014570] When zooming or scrolling on a graph with logaritmic scales for ...
Status: CONFIRMED
Alias: None
Product: VCL TeeChart
Classification: Unclassified
Component: Series (show other bugs)
Version: unspecified
Hardware: All All
: Normal major
Target Milestone: ---
Assignee: Steema Issue Manager
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-11-20 17:16 EST by narcís calvet
Modified: 2013-11-20 10:02 EST (History)
0 users

See Also:
Chart Series: ---
Delphi / C++ Builder RAD IDE Version:


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Description narcís calvet 2013-11-20 10:02:11 EST
When zooming or scrolling on a graph with logaritmic scales for the both the left and the bottom axis, lines which do not have any point or only 1 point within the graph "window" are drawn wrong. The example draws three lines, line green and blue should always be on top of each other. but are not after zooming in on the area containing the red line.

As in most applications, the ranges of the axis are determined by the program specification. So there's no way to change that. The green and blue line are both points on the same line, which should be a straight line in a log-log graph. This line should 'touch' the red line in one point. So I started this part of the application by plotting only two points. Should be enough when plotting a straight line (I thought). When zooming in to check if the line did indeed touch the red line I discovered it did not. After checking twice where I did make the mistake in my code, I found out it was not a mistake in my code. Of course I can work around it, by converting all coordinates from the log-log domain, using linear axis en adjusting the labels, but this should not be necessary.

Find attached project reproducing the issue. It also occurs in .NET version.
Probably same as TV52014805 [created:2009-11-20T17:16:52.000+01:00 reported by:narcis@steema.com reported in version:9.0 (TeeChart VCL)]