Re: [sage-support] How to calculate the affine coordinats of a point

2011-07-15 Thread Johannes
a very easy example would be this: sage: p1 = vector([-3,1,1]) sage: p2 = vector([1,-3,1]) sage: p = vector([0,-2,1]) #now i'm looking for some x,y such that #x * p1 + y * p1 == p x,y = var('x,y') sage: assume(x > 0) sage: assume(y > 0) sage: solve([x * p1 + y * p2 == p],x,y) [] #but: x = 1/4 a

Re: [sage-support] Re: psi function.

2011-07-15 Thread Michael Orlitzky
On 07/13/2011 04:29 PM, robin wrote: > Hello Michael > > thanks for this. > > Mathematica allows you to specify the metric by which you measure > simplicity (actually, it's called "ComplexityFunction" and IIRC there > are five or six builtins). > > As for sage, how about just counting > the numb

Re: [sage-support] Re: how to choose return values from solve

2011-07-15 Thread Jose Guzman
On 15/07/11 21:49, achrzesz wrote: t=var('t') taum, tauh, m = var('taum, tauh, m') f(t) = (1-e^(-t/taum))^m*(e^(-t/tauh)) d=diff(f(t),t) d1=(d==0).full_simplify() print d1.solve(t) awesome! I guess one will have first to simplify the equation if this looks complicated before executing the s

[sage-support] Re: Can't get Sage Started on Windows

2011-07-15 Thread Volker Braun
On Friday, July 15, 2011 7:59:33 PM UTC+2, pblelloch wrote: > > Unknown error creating VM (VERR_VMX_MSR_LOCKED_OR_DISABLED) >> Is there anything in particular that I need to do to allow the virtual >> box to run? Is this the only way to run Sage on a Windows computer? > > This means that you a) en

[sage-support] Re: how to choose return values from solve

2011-07-15 Thread achrzesz
t=var('t') taum, tauh, m = var('taum, tauh, m') f(t) = (1-e^(-t/taum))^m*(e^(-t/tauh)) d=diff(f(t),t) d1=(d==0).full_simplify() print d1.solve(t) -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegro

Re: [sage-support] Re: how to choose return values from solve

2011-07-15 Thread Nin
On 15/07/11 19:55, achrzesz wrote: sage: assume(t,'real') sage: solve(diff(myHH,t),t) [t == 1/10*log(31)] Thanks a lot!. This work for the special case of myHH, where: myHH(t) =(1-e^(-t/0.1))^3*(e^(-t/10.) However, for a more general function: sage: t=var('t') sage: taum, tauh, m = var('

Re: [sage-support] Re: Can't get Sage Started on Windows

2011-07-15 Thread Paul Blelloch
I got further by going back to a single processor. This time it got further, loading Fedora and then bringing me into what looks like a Linux terminal window. However still no Sage. I'm kinda thinking that I should try this at home on Ubuntu, and wait for Sage to come out with a native Windows p

[sage-support] Re: Can't get Sage Started on Windows

2011-07-15 Thread Harald Schilly
> VERR_VMX_MSR_LOCKED_OR_DISABLED Google pointed me to this thread: http://forums.virtualbox.org/viewtopic.php?f=6&t=31120 Maybe it helps? Technically, you can also try VMware. H -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to

[sage-support] Can't get Sage Started on Windows

2011-07-15 Thread pblelloch
I wanted to try Sage on my Windows computer. I downloaded the Virtual Box software, and imported the Sage-4.7.ova file as an appliance. So far so good, but when I try to start it I get the following error from VirtualBox: Failed to open a session for the virtual machine Sage-4.7 Unknown error c

[sage-support] Re: Can't get Sage Started on Windows

2011-07-15 Thread Paul Blelloch
P.S., I never did get asked to setup a username or password in the VirtualBox, so I'm thinking that there was something missing in the processing of importing Sage. On Fri, Jul 15, 2011 at 10:52 AM, pblelloch wrote: > I wanted to try Sage on my Windows computer. I downloaded the Virtual > Box s

[sage-support] Re: how to choose return values from solve

2011-07-15 Thread achrzesz
sage: assume(t,'real') sage: solve(diff(myHH,t),t) [t == 1/10*log(31)] -- 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/gro

Re: [sage-support] Very slow matrix calculations in SAGE

2011-07-15 Thread Henry de Valence
On Thu, 2011-07-14 at 05:32 +0200, William Stein wrote: > Sage is probably just using some completely generic general > implementation of "kernel" for matrices. > There is an SVD implementation in Sage, which computes the Singular > Value Decomposition of your matrix quickly: > > sage: M = matrix(

[sage-support] how to choose return values from solve

2011-07-15 Thread Nin
Dear Sage mailing list I am having a hard time to get the maximum value (numerically/analytically) to one equation. In concrete I want to solve: sage: t= var('t') # dependent variable sage: taum, tauh, m = var('taum, tauh, m') # parameters sage: f(t) = ((1-e^(-t/taum))^m)*(e^(-t/tauh)) Now i

[sage-support] Re: Polynomials Mod 7

2011-07-15 Thread luisfe
On Jul 14, 3:23 am, Mel wrote: > Hi, > > I've been having an issue with a program I've written in sage. I need > to calculate a polynomial mod 7. When I do this using the command > line, I don't have any trouble. Example: > > sage: x = var('x') > sage: y = var('y') > sage: IntegerPolyRing. = ZZ