[sage-edu] Re: sagelet - calculus in two variables - differential
On 9 Bře, 16:03, Rob Beezer wrote: > > Consider adding a screenshot and your code to the Interact/Calculus > section of the Sage wiki. Jason or myself will eventually split off a > multivariate section and then add in more of our own sagelets. > Done. I added also another simple sagelet which is nice to show local minima and maxima: http://wiki.sagemath.org/interact/calculus#A3Dgraphwithpoints I wonder if it is possible to restrict the 3Dplot only to those x and y which satisfy a set of inequalities (can be used to show absolute maxima and minima). Is there any idea how to do this? Robert --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
[sage-edu] Re: sagelet - calculus in two variables - differential
On Mar 10, 2:37 am, "ma...@mendelu.cz" wrote: > Done. I added also another simple sagelet which is nice to show local > minima and > maxima:http://wiki.sagemath.org/interact/calculus#A3Dgraphwithpoints Looks good! Thanks for contributing. > I wonder if it is possible to restrict the 3Dplot only to those x and > y which satisfy a set of inequalities (can be used to show absolute > maxima and minima). Is there any idea how to do this? I've had the same thought as I was in class discussing absolute max and min for functions of two variables on various domains (open/ closed, bounded/unbounded, etc). Quick-and-dirty might be to define your calculus function as a seperate Python function and have the Python function return a single value (like zero) for any point not in the domain of interest. You'd just have to remember the distinction for those points. Even better would be to return something like "None" if that got passed to JMOL right (I don't know anything about how Sage passes the plot information into JMOL). I wonder if it would be possible to have a new argument to plot3d() that would accept a boolean function that checks each (x,y) coordinate considered in the plot routine and returns True/False if the point is inside/outside the desired domain? Then it would just be a matter of creating a callable function of two variables that encodes the conditions for membership in the domain. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
[sage-edu] Two opportunities - reply off-list
Dear Sage-edu, It's been great to see the renewed activity the last four months or so, incuding much that came out of the Joint Meetings and now the ongoing Primer project. I've had two projects on the back burner that I would now like to work on for the next month or two, and welcome any assistance or ideas for. 1. The Journal of Online Mathematics and its Applications (JOMA) is now part of Loci, the MathDL (national digital library, NSF/MAA funded). As far as I know, they have not yet had anything on Sage. I spoke with one of the editors about this in January and he sounded quite interested. See Loci: Developers (http://www.joma.org/mathDL/ 55/) and Loci: Resources (http://www.joma.org/mathDL/47/) for examples, including no fewer than three articles by Geogebra's M. Hohenwarter and his collaborators, from 2007. I could also envision some things landing under "Commentaries" etc., but for now I think that an intro to using Sage and some more technical article like this one: http://www.maa.org/joma/Volume7/Hohenwarter2/index.html would be appropriate to submit. 2. The MAA has a series of PREP workshops that it sponsors, see http://www.maa.org/prep/ for more details. I have spoken with the program officer of this, and they are particularly keen on online ones (among other reasons, more bang for the buck). This summer there will be one on Geogebra (http://www.maa.org/prep/2009/geogebra.html - wdj, you know the organizer) and there doesn't seem any reason that one on Sage would not be seriously considered as long as we had our act together. They have not announced any dates yet but it sounds like early summer would be the best time for initial proposals. I also have some other materials from the Geogebra organizer, so I think this would be a real possibility, though it would require a LOT of work on the part of the organizers in terms of logistics for running an online workshop (they usually run a week) in the summer of 2010. Alternately, if there is a Sage Days concurrent with it, that could work too, but I don't know that usual Sage Days funding sources would be usable for this. Again, if anyone has ideas or would like to help put something like one of these together, please reply off-list. - kcrisman --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
[sage-edu] Re: sagelet - calculus in two variables - differential
ma...@mendelu.cz wrote: > > On 9 Bře, 16:03, Rob Beezer wrote: > >> Consider adding a screenshot and your code to the Interact/Calculus >> section of the Sage wiki. Jason or myself will eventually split off a >> multivariate section and then add in more of our own sagelets. >> >> > > Done. I added also another simple sagelet which is nice to show local > minima and maxima: > http://wiki.sagemath.org/interact/calculus#A3Dgraphwithpoints > > I wonder if it is possible to restrict the 3Dplot only to those x and > y which satisfy a set of inequalities (can be used to show absolute > maxima and minima). Is there any idea how to do this? > > Carl Witty's implicit_plot3d function has the code to create "holes" in the function like what is being discussed. That patch is slowly maturing towards inclusing in Sage. See http://trac.sagemath.org/sage_trac/ticket/5249 Jason --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
[sage-edu] Re: sagelet - calculus in two variables - differential
Will that allow one to *explicitly* restrict a domain to a subset of what is the biggest possible? In other words, could I plot x^2+y^2 *only* above the circle (x-2)^2 + (y-3)^2=4? On Mar 10, 12:03 pm, jason-s...@creativetrax.com wrote: > ma...@mendelu.cz wrote: > > > On 9 Bře, 16:03, Rob Beezer wrote: > > >> Consider adding a screenshot and your code to the Interact/Calculus > >> section of the Sage wiki. Jason or myself will eventually split off a > >> multivariate section and then add in more of our own sagelets. > > > Done. I added also another simple sagelet which is nice to show local > > minima and > > maxima:http://wiki.sagemath.org/interact/calculus#A3Dgraphwithpoints > > > I wonder if it is possible to restrict the 3Dplot only to those x and > > y which satisfy a set of inequalities (can be used to show absolute > > maxima and minima). Is there any idea how to do this? > > Carl Witty's implicit_plot3d function has the code to create "holes" in > the function like what is being discussed. That patch is slowly > maturing towards inclusing in Sage. > Seehttp://trac.sagemath.org/sage_trac/ticket/5249 > > Jason --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
[sage-edu] Re: sagelet - calculus in two variables - differential
On Tue, Mar 10, 2009 at 11:20 AM, Rob Beezer wrote: > > Will that allow one to *explicitly* restrict a domain to a subset of > what is the biggest possible? > > In other words, could I plot x^2+y^2 *only* above the circle (x-2)^2 + > (y-3)^2=4? For the current implicit_plot3d, if you mean above the interior of the circle, then this would partly work. The plotting draws quadrilaterals in a grid, and you can tell it to discard any quadrilateral that has a vertex outside the circle. So you could get your plot, but it would have a jagged outline, unless you used a very large plot_points setting (which would make it very slow). (This isn't technically accurate, but it's close enough to understand the issues here.) If you mean above the boundary of the circle, then no -- there would be no quadrilaterals with all four vertices directly above the boundary of the circle, so all quadrilaterals would be discarded. Of course, implicit_plot3d is a bad way to plot this function, because it will be far slower than plot3d. Carl --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
[sage-edu] Re: sagelet - calculus in two variables - differential
Hi Carl, Yes, I meant over the interior. ;-) Thanks for the explanation of what's coming in implicit_plot3d() - sounds like it will be a good addition. > > In other words, could I plot x^2+y^2 *only* above the circle (x-2)^2 + > > (y-3)^2=4? > Of course, implicit_plot3d is a bad way to plot this function, because > it will be far slower than plot3d. Am I missing a way to plot this function, so I only see the portion above (the interior of) the circle, by using plot3d()? Rob --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "sage-edu" group. To post to this group, send email to sage-edu@googlegroups.com To unsubscribe from this group, send email to sage-edu+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-edu?hl=en -~--~~~~--~~--~--~---
