On 2017-02-23 12:24-0000 Peter Williams wrote: > I need to label my contours with floating point values. However, I seem > to get strange results. > I have a simplified example of what occurs in the program below. It > draws an ellipse with contour value 1.0e10, i.e. x*x/4 + y*y = 1.0e10. > The contour is good. The label is written as 1.0?#???10 where ? stands > for a character I cannot recognise in this context. What am I doing wrong?
Hi Peter: As a general rule (for everybody here), check with the examples first to see what they do since those examples are tested thoroughly before each release. In this case examples/c/x09.c is an example of contour labels which do work, but I notice the data values do not have the huge scale that yours do (so our testing never tests the exponential option that is documented in <http://plplot.sourceforge.net/docbook-manual/plplot-html-5.12.0/pl_setcontlabelformat.html>). As a first step, could you let us know your exact platform and also build example 9 for yourself to confirm it works fine on that platform? Assuming that does work, then as a second step to make sure all other aspects of your own simplified testing example are working properly what happens if you scale your example, (e.g., set the above 1.0e10 value to something like 1.0) to a non-exponential range, and use pl_setcontlabelformat( 4, 3 ); like example 9 does? If that also works (as it should if example 9 works for you), then I would scale your example to both single-digit positive and negative exponents, and also explore what happens if you change the parameters of pl_setcontlabelformat. That is, explore the problem a little to give us an idea of the conditions (compared to the scale of our example 9) where you are getting bad labels. I have just taken a quick look at the contour labelling code in src/plcont.c (which we haven't looked at in years), and its self-documentation says it should be able to handle the case of positive exponents with 4 digits or negative exponents with 3 digits but your results indicate there might be some bug there so your explorations of the problem may help us to find that bug assuming it exists. 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 __________________________ ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Plplot-general mailing list Plplot-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-general
