Comments on: WPF & Silverlight Charting: A Logarithmic Axis

By: cplotts

cplotts — Tue, 15 Nov 2011 21:35:13 +0000

For fun, here is an image to the new chart:

By: cplotts

cplotts — Tue, 15 Nov 2011 21:30:15 +0000

@Justin, two things.

First … I have updated the test harness that you have downloaded. I was previously only showing a logarithmic axis (in the correct direction) on the Y axis … and not really focusing on the line series. It was working … but the minimum and maximum values weren’t showing a range to where you could see the data. That is, the sample data occurs at values less than 100.

In the updated harness, I have created a derived logarithmic axis that better shows off the line series.

So, in other words, the fact that no data displays in my test harness is likely not related.

Second … the development release 4 of this charting component … may or may not be completely compatible with the February 2010 release of the WPF Toolkit … I do not know, I have not tried this specific incantation of the logarithmic axis against it. If it doesn’t work, it shouldn’t be too hard to fix … so that it does work … but it may not be a drop-in.

By: Justin

Justin — Tue, 15 Nov 2011 19:28:05 +0000

@cplotts
Thanks for the quick reply. I’m looking into it still and haven’t yet come up w/ a reasonable explanation. Consequently, I have also downloaded the DataVisualizationDemos4 project you have linked above, and when selecting to see the “Logarithmic Axis” demonstration, the grid appears but the data line does not. Could the fact no data displays there be related as well?

As a background, I am using the February 2010 Release of the WPF Toolkit and .Net Framework 4 in Visual Studio 2010.

By: cplotts

cplotts — Mon, 14 Nov 2011 22:33:46 +0000

I have never used the logarithmic axis in that way, but it should be possible. That being said, I wouldn’t be surprised if there is an arbitrary limitation in the charting code.

I would debug into it if I were you.

If you are still hitting a brick wall after debugging into it, compose a simple project for me and I’ll see if I can take a quick look myself.

By: Justin

Justin — Mon, 14 Nov 2011 21:11:13 +0000

I just recently started playing around with WPF for a work project, and I appear to be having some issues with this axis. My plot is supposed to be a column series with a date/time axis along the X, and a logarithmic axis in the Y direction. When I attempt to render, no values appear on my chart. If I change the column series to another type, such as scatter, area, or line series, my data renders. Do you have any ideas on why my columns don’t appear?

As I said, I am new to WPF (I am a Java developer mostly), so if there is more info I need to provide let me know. Thanks!

By: cplotts

cplotts — Thu, 01 Sep 2011 16:06:37 +0000

@Morgan, I’m pretty sure you can do that … but I really don’t have the time to solve it for you.

I did take a quick look, though, and my axis labels were showing up as 0.01 after setting the Minimum to 0.01 and returning a few more grid lines … so this seems like something you might be doing/causing on your side.

By: Morgan

Morgan — Tue, 30 Aug 2011 21:30:50 +0000

Thanks, another quick question, currently if you set a Major value to less the 0.01 it formats it to 0, is there any quick easy way to change the formating?

By: cplotts

cplotts — Mon, 29 Aug 2011 20:20:04 +0000

@Morgan, ha , I can’t win!

I fixed the link.

By: Morgan

Morgan — Mon, 29 Aug 2011 19:44:36 +0000

Thanks for the quick response, I am using WPF4.0/Silverlight 4.0 so hopefully this will fix the problem. The only issue is that you posted a bad link.

By: cplotts

cplotts — Mon, 29 Aug 2011 19:30:10 +0000

@Morgan, my bad ... that is, if you were using the WPF 4.0/Silverlight 4.0 version of the code that I recently uploaded. It had a mistake in it that I have corrected. I have uploaded the correct code to the same link.