On 2009-05-26 09:02+0200 Robert Pollak wrote: > Alan W. Irwin schrieb: >> [...] I would suggest you >> handle aspect ratio (question 2) above by sticking to one of the >> pre-existing PLplot coordinate systems to specify the semimajor and >> semiminor axes of the ellipse. Probably you would want to use world >> coordinates (and similarly you would want to use world coordinates to >> specify the centre of the ellipse), but the choice of coordinate system >> really depends on how convenient those coordinates would be for your >> proposed use case(s), see my question above. > > Let me mention that example x32c.c shows a use case for not using world > coordinates: drawing an undistorted circle as a marker.
Robert, I am glad you brought this up since there is an important distinction between circular symbols (which, as you suggest, must remain circular regardless of aspect ratio), and a geometrical figure (whose axis coordinates will probably be world coordinates). Hez, can you confirm your intended use case was for a geometrical figure rather than a symbol? Clearly, in the case of example 32 a circular symbol was meant. examples/python/test_circle.py contains a number non-unicode and unicode ways of generating such symbols. Example 1 and Example 6 show additional methods of generating circular symbols. I suggest example 32 be simplified to use one of those methods rather than using the local "plcircle" function that is currently implemented in x32c.c to duplicate that already-existing PLplot core functionality for generating circular symbols. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ Register Now for Creativity and Technology (CaT), June 3rd, NYC. CaT is a gathering of tech-side developers & brand creativity professionals. Meet the minds behind Google Creative Lab, Visual Complexity, Processing, & iPhoneDevCamp asthey present alongside digital heavyweights like Barbarian Group, R/GA, & Big Spaceship. http://www.creativitycat.com _______________________________________________ Plplot-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/plplot-devel
