Showing Standard deviation (errorbar) in Radar Plot / on rotated axes

In my radarplot I calculate the mean of certain values which I show on each one of the axes. I would now like to add an errorbar.

My issue is that I cannot rotate the errorbar in the same way the 'normal' points are rotated (using pol2cart). You can see that result in the picture kiviat1.

My idea to work around this was to just add every errorbar as their own plot. You can see that result in kiviat2. As you can see, the errorbar is rotated, but I cannot find a way to have a nice marker that will actually make it look like a regular standard deviation.

I would be glad to get some new solution ideas. I have also attached an example testscript and the radar plot function (lines 227 and following are the ones where the points are plotted).

[dpb]

I've only got one idea and you're probably not going to like it... :)

My first thought was you might be able to create additional axes and use view to change azimuth angle to rotate the y-axis to be parallel to the desired angle and then perhaps the HG rendering would handle it for you -- but, no, the bars and plots are rotated but the error bars at the ends stay horizontal.

So, the only ending thought I have is that would have to just draw the errorbars yourself as discrete lines at the right position and angles...

[Freya H]

You are absolutely right, I do not like it :D But thanks anyways - I guess that is what I'm going to try now.

It's just going to be so annoying as the number of axes (and thus the angles of the axes) can vary .__.

[dpb]

It should be possible to do the required geometry transformation based on that number/angle and wrap in a function so that you only then have to deal with the details once.

Answer 1

[Freya H]

@dpb: thanks again for the final idea & you are right, it wasn't all to difficult to set up all bars at once.

Not the nicest solution and something is slightly off in the transformation (angles are not exactly 90 degrees), but I didn't care enough to fix it as it's barely noticeable.

This function now creates the kiviat diagram including errorbars:

[dpb]

Bravo! Looks good to me...I'd never notice any off-normal projection if weren't mentioned and I'm not sure I can really tell even when told...