On Fri, May 1, 2009 at 9:31 PM, Thomas Savitsky <tjsavit...@gmail.com> wrote: > > On Fri, May 1, 2009 at 8:05 PM, William Stein <wst...@gmail.com> wrote: >> >> On Fri, May 1, 2009 at 4:58 PM, Thomas Savitsky <tjsavit...@gmail.com> wrote: >> > Hello all, >> > >> > I've noticed that the function find_minimum_on_interval makes no attempt to >> > find "the" minimum on the interval as the documentation implies, but rather >> > "a local" minimum. I imagine this may be a source of confusion for other >> > new users as well. Rather than treating this as a bug, may I suggest >> > changing the documentation for this function to reflect that it only finds >> > a >> > local minimum and adding an additional function which searches for a global >> > minimum? >> >> +1 Can you provide a few examples for the docstring that illustrate this? > > Do these work? > > sage: h(x) = -sin(x) - 2*sin(2*x) > sage: h.find_minimum_on_interval(0, 2*pi) > (-1.3271810224585345, 3.8298351449342838) > But there is another local minimum at h(0.8666760871050464) = -2.73581510406 > > > sage: find_minimum_on_interval(x*(x-1)*(x+1), -2, 2) > (-0.38490017945975047, 0.57735026913115706) > The minimum on this interval is the endpoint h(-2) = 6. > > > sage: find_minimum_on_interval((x-2)*(x-1)*x*(x+1) - x, -2, 2) > (-0.43749999999999994, -0.49999999973911674) > > but > sage: find_minimum_on_interval((x-2)*(x-1)*x*(x+1) - x, 0, 2) > (-2.6642135623730949, 1.7071067879138031) > > --Thomas >
Thanks. I've opened a trac ticket: http://trac.sagemath.org/sage_trac/ticket/5960 William --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
