[sage-support] Re: Problem with sagecell server installation
I'll try to test it. But if I remember correctly, I had to upgrade ipython first and then install trac 12719. Otherwise ./sage -br fails to start sage. Robert Dne pondělí, 17. září 2012 22:39:31 UTC+2 Jason Grout napsal(a): On 9/17/12 12:29 PM, kcrisman wrote: Could one of you post a (cleaned up) version of this somewhere on the wiki, analogous to the Sage server install wiki pages? This looks like a fairly circuitous route, with instructions from random tickets, for someone unfamiliar with the cell server to follow. I just posted a new sagecell spkg and cleaned up the instructions: https://github.com/sagemath/sagecell/issues/344 I haven't tested these very well yet, though. Jason -- You received this message because you are subscribed to the Google Groups sage-support group. 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. Visit this group at http://groups.google.com/group/sage-support?hl=en.
[sage-support] Strange results with multivariate resultants
I had to workaround against this counterintuitive results. 5.2 and 5.3 on linux x86_64 sage: K.x1,x2,x3=PolynomialRing(QQ) sage: p1=(x2-1)*(x3+2) sage: p2=(x2-1)*(x3+3) sage: p1.resultant(p2) 1 sage: K_.x2,x3=PolynomialRing(QQ) sage: p1_=K_(p1) sage: p2_=K_(p2) sage: p1_.resultant(p2_) 0 sage: gp.polresultant(gp(p1),gp(p2)) 0 -- You received this message because you are subscribed to the Google Groups sage-support group. 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. Visit this group at http://groups.google.com/group/sage-support?hl=en.
Re: [sage-support] Strange results with multivariate resultants
Hi, I'm not sure if I understand what is counterintuitive about the results. * Georgi Guninski gunin...@guninski.com [2012-09-18 16:55:37 +0300]: sage: K.x1,x2,x3=PolynomialRing(QQ) sage: p1=(x2-1)*(x3+2) sage: p2=(x2-1)*(x3+3) sage: p1.resultant(p2) 1 This is the resultant of p1 and p2 w.r.t. x1 (the first variable of K). sage: K_.x2,x3=PolynomialRing(QQ) sage: p1_=K_(p1) sage: p2_=K_(p2) sage: p1_.resultant(p2_) 0 The resultant of p1 and p2 w.r.t. x2 (the first variable of K_). sage: gp.polresultant(gp(p1),gp(p2)) 0 I'm not entirely sure what gp.polresultant() does, but it seems it computes the resultant w.r.t. variable() sage: gp(p1).variable() x2 The following is strange though: sage: gp.polresultant(p1,p2,x1) 0 # this should be 1? sage: gp.polresultant(p1,p2,x2) 0 sage: gp.polresultant(p1,p2,x3) x2^2 - 2*x2 + 1 Am I missing something here? julian -- You received this message because you are subscribed to the Google Groups sage-support group. 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. Visit this group at http://groups.google.com/group/sage-support?hl=en.
[sage-support] Plotting (non-compact) polyhedra and (half) infinite rays/lines
The plot routine for polyhedra (and also the render_solid and the render_wireframe method) seem to plot only part of the polyhedron. Take as an example q1=Polyhedron( vertices=[[0,0]], lines=[[-2,1]], rays=[[0,42]]) q.plot() Here only the line [-2,1] and a strip of length 1 in direction [0,1] is plotted. Even worse q.plot(ymin=-3,ymax=3,xmin=-3,xmax=3) gives only part of the strip, which could be contained in the image. As very simple example of this phenomenon is obtained by trying to plot a half infinite ray: p=Polyhedron(rays=[[2,4]]) p.plot(ymin=-3,ymax=3,xmin=-3,xmax=3) which plots nothing else than the vector (1,2). The same works is true for lines. Is this intended behavior? Is there a way to plot half-infinite rays? If not, should there be way to do that? One could asked the same questions for non-compact polyhedra in 3 dimensional space. moritz -- You received this message because you are subscribed to the Google Groups sage-support group. 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. Visit this group at http://groups.google.com/group/sage-support?hl=en.
[sage-support] Re: Plotting (non-compact) polyhedra and (half) infinite rays/lines
There is not enough space on your screen to plot non-compact polyhedra, so what exactly do you expect as output? Right now, the compact part plus (minkowski sum) the interval (origin, ray generator) is drawn. I guess you expect the whole half plane clipped by the plot window? How big should the plot window be if you only give it the half plane? On Tuesday, September 18, 2012 5:17:42 PM UTC+1, moritz wrote: The plot routine for polyhedra (and also the render_solid and the render_wireframe method) seem to plot only part of the polyhedron. Take as an example q1=Polyhedron( vertices=[[0,0]], lines=[[-2,1]], rays=[[0,42]]) q.plot() Here only the line [-2,1] and a strip of length 1 in direction [0,1] is plotted. Even worse q.plot(ymin=-3,ymax=3,xmin=-3,xmax=3) gives only part of the strip, which could be contained in the image. As very simple example of this phenomenon is obtained by trying to plot a half infinite ray: p=Polyhedron(rays=[[2,4]]) p.plot(ymin=-3,ymax=3,xmin=-3,xmax=3) which plots nothing else than the vector (1,2). The same works is true for lines. Is this intended behavior? Is there a way to plot half-infinite rays? If not, should there be way to do that? One could asked the same questions for non-compact polyhedra in 3 dimensional space. moritz -- You received this message because you are subscribed to the Google Groups sage-support group. 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. Visit this group at http://groups.google.com/group/sage-support?hl=en.
[sage-support] Re: Plotting (non-compact) polyhedra and (half) infinite rays/lines
Thanks for the fast reply! On Tuesday, September 18, 2012 6:24:29 PM UTC+2, Volker Braun wrote: There is not enough space on your screen to plot non-compact polyhedra, so what exactly do you expect as output? well, the same is true for function plotting but f=3*x; plot(f) gives a reasonable result. I would expect the plot function to choose good boundaries. Right now, the compact part plus (minkowski sum) the interval (origin, ray generator) is drawn. I guess you expect the whole half plane clipped by the plot window? exactly! How big should the plot window be if you only give it the half plane? Possibly a good heuristic would be to leave the plot as big as it is automatically (which already makes some choices, e.g p=Polyhedron(vertices=[[0,0]]);p.plot() ) but don't only plot the Minkowski sum but also everything else, that would belong to the polytope within these boundaries. In the case of the half plane, it depends on the which half plane we are talking about. For q=Polyhedron(lines=[[1,0]], rays=[[1,2]]); q.plot() the standard output looks fine to me, but for p=Polyhedron(lines=[[1,2]], rays=[[0,1]]);p.plot() or the example above I would like to see more. Since the Vrepresentation is unique and already given, it shouldn't be to hard to get good boundaries. (And this has been done already..) -- You received this message because you are subscribed to the Google Groups sage-support group. 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. Visit this group at http://groups.google.com/group/sage-support?hl=en.
