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Logarithmic scale bug

Posted: Wed May 12, 2010 12:26 pm
by 15656109
In the attachment there are two TChart with logarithmic scale and the same data. First is WPF TChart (ver. 4.0.2010.13053), second WinForms TChart (ver. 2.0.2987.19069).
wpf.png
wpf.png (8.51 KiB) Viewed 10930 times
wf.png
wf.png (4.56 KiB) Viewed 10932 times
You can see: pictures are quite different! Why??

Re: Logarithmic scale bug

Posted: Wed May 12, 2010 12:43 pm
by 15656109
You can easy check correctness of WPF TChart with logarithmic scale: make TChart with logarithmic Y axis, set MinValue to 100, MaxValue to 1000 and add one point with Y = 316.2 ( it is sqrt (100*1000)). This point must be in the middle of TChart between bottom and top. And it will not be in the middle!

Re: Logarithmic scale bug

Posted: Fri May 14, 2010 9:29 am
by 15656109
Steema people, please!

Did you check this issue? It's critical because of wrong data presentation! Can you fix it?

Re: Logarithmic scale bug

Posted: Fri May 14, 2010 11:02 am
by yeray
Hi neurosoft,

It seems that the axes' logarithmic property has been broken for some reason with the latest build (v4.0.2010.13052), with WinForms. In WPF it still seems to work fine.
I've added it to the defect list to be fixed asap (TF02014882). Thanks for reporting it.

Re: Logarithmic scale bug

Posted: Fri Jun 11, 2010 4:40 pm
by yeray
Hi neurosoft,

We will close the (TF02014882) because both in WinForms and WPF the following code describes a straight line, which we think would be the expected:

Code: Select all

            tChart1.Aspect.View3D = false;
            tChart1.Legend.Visible = false;

            tChart1.Axes.Left.Logarithmic = true;
            tChart1.Axes.Left.SetMinMax(100, 1000);
            tChart1.Axes.Bottom.SetMinMax(0, 20);

            Steema.TeeChart.Styles.Points points1 = new Steema.TeeChart.Styles.Points(tChart1.Chart);
            //Steema.TeeChart.WPF.Styles.Points points1 = new Steema.TeeChart.WPF.Styles.Points(tChart1.Chart);

            for (int i = 0; i < 20; i++)
            {
                points1.Add(i * (1000 - 100) / 20 + 100);
            }

Re: Logarithmic scale bug

Posted: Wed Jun 23, 2010 11:08 am
by 15656109
Hi Yeray!

Logarithmic scale bug is very serious!

I have changed your sample a little to see points from 10 to 1000.

Please see attached pictures

Picture N 1 (WPF TChart Version=4.0.2010.27963, logarithmic scale) is wrong! It's look like Picture N 2 (WPF TChart Version=4.0.2010.27963, linear scale).
Picture N 1 must be look like as Picture 3 (Windows Forms TChart Version=2.0.2987.19069, logarithmic scale)! Picture 4 (Windows Forms TChart Version=2.0.2987.19069, linear scale) is here only to compare with others.

Please fix this bug, it's very serious, because of it we have to use old TChart versions and can't go to using WPF TChart!!
Log.png
Log.png (38.94 KiB) Viewed 10742 times

Re: Logarithmic scale bug

Posted: Tue Jun 29, 2010 1:23 pm
by 15656109
Hi, Steema people!

Why didn't you response to my cry from the heart? Can you fix this bug with logarithmic axes? Because of this bug it's impossible to use latest TChart!

Re: Logarithmic scale bug

Posted: Wed Jun 30, 2010 6:47 am
by yeray
Hi neurosoft,

We haven't forgotten this. We are investigating it and we'll be back here asap.

Re: Logarithmic scale bug

Posted: Wed Jun 30, 2010 11:59 am
by yeray
Hi neurosoft,

We've found the problem and solved it. The fix will be available with the next maintenance release.
In the meanwhile here it is an ugly workaround:
After: tChart1.Axes.Left.Logarithmic = true;
Run: tChart1.Axes.Left.Horizontal = tChart1.Axes.Left.Horizontal;

Re: Logarithmic scale bug

Posted: Fri Jul 02, 2010 9:44 am
by 15656109
Hi Yeray!

It works! Thank you!!