Yes, exactly. For instance if I wanted to make a polar bar chart showing the distribution of angles separating a collection of lines at their intersections, I would only need to display one quarter of the polar plot, the first quadrant, from 0-90 degrees. If I wanted to display the orientation of, say, a fault on the surface of the Earth, I’d need 180 degrees, but I might want to use the northern half of the circle (orientations ranging from West to East (-90, 90)) or perhaps the eastern half (ranging from (0, 180)).
Ideally, the user would be able to specify both thetamin and thetamax, and also an offset describing the location of theta=0, because in some applications it doesn’t make sense for zero to be in its traditional polar-coordinates location at the right hand side. E.g. in a geographic context, where the angles being displayed are compass headings, it is traditional to put zero (north) at the top. Putting zero at the top would also make sense if you were plotting data that corresponded to angular deviations to the left and right from some specified path.
Some portion of this functionality has been implemented in the “windrose” module, see:
but with a mind toward a particular kind of application (windrose diagrams obviously :). But I think allowing users to specify (thetamin, thetamax, offset) would be a very generally applicable improvement.
On Oct 17, 2008, at 11:06 AM, Michael Droettboom wrote:
No, it’s not possible now. Just so I’m clear – you’re suggesting plotting on a wedge from theta_1 to theta_2? Seems doable with a little work.
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