[sage-support] Re: parametric_plot3d appears to not give the correct axes values, also steals keyboard
I filed a ticket at http://trac.sagemath.org/sage_trac/ticket/6002. -- Bill --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: parametric_plot3d appears to not give the correct axes values, also steals keyboard
On Wed, May 6, 2009 at 12:28 PM, Alden alden.wal...@gmail.com wrote: 0) sagenb.com is awesome, especially since Mathematica 7 takes up 100% of my processor at all times under Ubuntu 9.04. Glad to hear it :). 1) When I run: parametric_plot( (cos(t), sqrt(2)*sin(t)) , (t,0,2*pi)) I get a nice 2d parametric plot, with the top of the ellipse clearly hitting close to 1.5 on the y-axis. When I run: parametric_plot3d( (cos(t), 1 , sqrt(2)*sin(t)), (t,0,2*pi)) The top of the ellipse really looks like it's at z=1, and the whole thing looks a lot like a circle. I realize that this is probably not a problem with sage and rather with whatever is doing the plotting, but I thought I should point it out. I think that this is a bug, but I can't find the source of the error very easily. I will open a Trac ticket to address this issue. Thanks for pointing it out! 2) Also, after clicking and dragging on the 3d plot, I can't type anywhere in firefox (the notebook or the address bar) until I click onto another tab and then back again. This may be a problem with java in my browser not taking the keyboard away from the applet. That's odd. Do you mean to say that even when you try to move focus away from the Java applet using your mouse, input is still captured? I myself use Sage on vanilla Ubuntu 9.0.4 with no difficulties. Maybe the problem is with your Java or web browser configuration. 3-more of a feature request than an error I guess) I have noticed from googling that there has been some discussion about creating a function from R^n to R^m. I am sure there is some good reason why this isn't the case, but I was curious about whether it would be possible to just automatically map everything over tuples of symbolic expressions, or make a tuple of symbolic expressions a symbolic expression itself. For example, why couldn't diff( (t, 2*t), t) (which gives the error that a tuple is not a symbolic expression) notice that the tuple is a tuple of symbolic expressions, and then just map itself over it to get (1,2). Also, then defining f(x,y) = (2*x, 2*y) seems like it would work. Similarly, what if there was a dot product function which just did the obvious thing when it was given two tuples of symbolic expressions? The reason that I am thinking about this is that it would be really awesome if I could tell my vector calculus class to do a line integral by defining what f(c(t)) =fc(t) and c(t) are and then just: integrate( dot( fc(t), diff( c(t), t), t, 0, 2*pi) rather than something like integrate( vector( (t,t^2,t^3) ).dot_product( diff( vector( (t,t,t) ), t ) ), t,0,2*pi) which is a little less intuitive. To address your diff example: it is simple enough in this case to do [diff(f, t) for f in (t, 2*t)]. I don't know what work is being done in Sage to help work with vector-valued functions, but maybe someone more familiar with the symbolic calculus component can chime in. One way to improve your line integral example would be to refactor it into a Python function in terms of f and fc, so that students could simply type: line_integral(f, fc). But since this is a math class, I understand if you do not want to go that in-depth into programming techniques. -- Bill --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: parametric_plot3d appears to not give the correct axes values, also steals keyboard
thanks! On May 6, 11:33 pm, William Cauchois wcauc...@u.washington.edu wrote: I filed a ticket athttp://trac.sagemath.org/sage_trac/ticket/6002. -- Bill --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: parametric_plot3d appears to not give the correct axes values, also steals keyboard
Sorry, I should have noted that everything I did here was on sagenb.com using firefox running on Xubuntu 9.04 On May 6, 12:28 pm, Alden alden.wal...@gmail.com wrote: 0) sagenb.com is awesome, especially since Mathematica 7 takes up 100% of my processor at all times under Ubuntu 9.04. 1) When I run: parametric_plot( (cos(t), sqrt(2)*sin(t)) , (t,0,2*pi)) I get a nice 2d parametric plot, with the top of the ellipse clearly hitting close to 1.5 on the y-axis. When I run: parametric_plot3d( (cos(t), 1 , sqrt(2)*sin(t)), (t,0,2*pi)) The top of the ellipse really looks like it's at z=1, and the whole thing looks a lot like a circle. I realize that this is probably not a problem with sage and rather with whatever is doing the plotting, but I thought I should point it out. 2) Also, after clicking and dragging on the 3d plot, I can't type anywhere in firefox (the notebook or the address bar) until I click onto another tab and then back again. This may be a problem with java in my browser not taking the keyboard away from the applet. 3-more of a feature request than an error I guess) I have noticed from googling that there has been some discussion about creating a function from R^n to R^m. I am sure there is some good reason why this isn't the case, but I was curious about whether it would be possible to just automatically map everything over tuples of symbolic expressions, or make a tuple of symbolic expressions a symbolic expression itself. For example, why couldn't diff( (t, 2*t), t) (which gives the error that a tuple is not a symbolic expression) notice that the tuple is a tuple of symbolic expressions, and then just map itself over it to get (1,2). Also, then defining f(x,y) = (2*x, 2*y) seems like it would work. Similarly, what if there was a dot product function which just did the obvious thing when it was given two tuples of symbolic expressions? The reason that I am thinking about this is that it would be really awesome if I could tell my vector calculus class to do a line integral by defining what f(c(t)) =fc(t) and c(t) are and then just: integrate( dot( fc(t), diff( c(t), t), t, 0, 2*pi) rather than something like integrate( vector( (t,t^2,t^3) ).dot_product( diff( vector( (t,t,t) ), t ) ), t,0,2*pi) which is a little less intuitive. -Alden --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
