On Apr 16, 12:49 am, "D. S. McNeil" <[email protected]> wrote: > > I'm not turning off warnings in numpy, though, since we use it under the > > hood only > > here. > > I'm confused. I was going to recommend numpy.seterr(all='ignore') > before I read this, maybe wrapping plot to restore the original state > after the call.. but now I'm not sure what kind of solution you want. > :^)
That was exactly my thought, that this is inappropriate. > In this case, the problem is being caused by the default parameters in > plot_slope_field. If you override headlength=0 with some small > number, there's no problem. IOW, > > P=plot_slope_field(g,(x,3,4),(y,-1,1),headlength=1e-8) > > works for me. FYI, it's the following few lines in Quiver._h_arrows at fault: > > minsh = self.minshaft * self.headlength > [....] > shrink = length/minsh > X0 = shrink * X0[np.newaxis,:] > Y0 = shrink * Y0[np.newaxis,:] > > Probably we should change the defaults and/or (if it's not done > already) ask our matplotlib friends to special-case 0 for no > arrowheads. > > Does that help? Nice catch! So it wasn't what I thought (though I admit I didn't have time to actually look at the backtrace much). I had to use Sage 4.4.4 today in a talk just to avoid this. Since it's a warning, it wouldn't show up in doctesting as a failure. Yes, it would be worth posting this as a pure pylab example (which I don't quite know how to do it as, naturally) upstream. See http://trac.sagemath.org/sage_trac/ticket/11208 (and also http://trac.sagemath.org/sage_trac/ticket/2922, which is tangentially related). - kcrisman -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
