Hi Hazen: On 2015-05-13 11:46-0400 Hazen Babcock wrote:
> > Hello Alan, Arjen, > > As I mentioned before, the FPE's in x25c, x30c and x33c are all coming from > the notcrossed() function in plfill.c. Hopefully you can provide some insight > as the authors. Basically the problem arises in a situation where the two > lines do not cross, but are not parallel. > In this situation this function > still calculates the x,y intersection. However, depending on the position and > orientation of the two lines this intersection can be way outside the range > of values that can be represented using (4 byte) integers. Do you recall if > functions that call this function expect to receive a valid intersection > point in this case? Or is it ok to just return zero? Hi Hazen: I have reviewed plfill.c, and the returned intersection from notcrossed is only used when status is zero. So I have (commit ID = b916d4b) considerably simplified noncrossed to do the PLINT transformation of the intersection and return those values _only_ when status = 0. This change solved all fpe problem for examples 25 and 30, but there are remaining fpe issues for fortran examples 21 and 33. The logic in noncrossed is pretty bullet-proof now so my prediction is those remaining fpe issues are completely independent of notcrossed or else there is a non-initialized variable somewhere in fortran examples 21 and 33. But I look forward to your definitive conclusion concerning those remaining fpe issues. 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); the Time Ephemerides project (timeephem.sf.net); PLplot scientific plotting software package (plplot.sf.net); 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 __________________________ ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
