2015-12-05 21:03:04 UTC+1, Emmanuel Charpentier: > > Plot2d() gracefully handles plotting a fnction undefined (in real terms) > on part of the plotting domain. For example : > plot(sqrt(x^2-1),(x,-3/2,3.2)) > displays two half-axes of hyperbole, and waons that some points have been > lost. > > plot3d() seems to lack this facility : an undefined point causes the loss > of al the plot. > > How would you handle this case ? I want to plot a function defined only > for some part of the plotting domain. I do not have an analytic definition > for the bounds of this domain (it is defined by an equation with no closed > form solution, but easily approximated by find_root()). >
An illustration: sage: plot(lambda x: sqrt(x^2 - 1), (-2, 2)) verbose 0 (2716: plot.py, generate_plot_points) WARNING: When plotting, failed to evaluate function at 99 points. verbose 0 (2716: plot.py, generate_plot_points) Last error message: 'math domain error' Launched png viewer for Graphics object consisting of 2 graphics primitives sage: plot3d(lambda x, y: sqrt(x^2 + y^2 - 1), (-2, 2), (-2, 2)) /opt/sage69b1/local/lib/python2.7/site-packages/sage/repl/rich_output/ display_manager.py:570: RichReprWarning: Exception in _rich_repr_ while displaying object: math domain error RichReprWarning, Graphics3d Object One workaround might be, if your function f sometimes returns complex output, to plot f(x) when real, and 0 otherwise. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
