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

2011-07-13 Thread William Stein
On Wed, Jul 13, 2011 at 6:51 PM, hdevalence wrote: > Hello, > > I'm having some trouble with some matrix calculations in SAGE. I'd > like to find the kernel of some matrices, but I think I'm doing > something wrong, because it's very slow. > > For example: > sage: M = matrix(RDF, 200,400, lambda i

Re: [sage-support] Polynomials Mod 7

2011-07-13 Thread William Stein
On Thu, Jul 14, 2011 at 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: IntegerP

[sage-support] Re: Graphics() objects and a histogram

2011-07-13 Thread Jason Grout
On 7/13/11 3:29 PM, David Monarres wrote: Hello all, Today I was working on a top-level histogram plotting function by exposing matplotlib's hist as a Graphics object Nice! Were you using http://trac.sagemath.org/sage_trac/ticket/9671 or doing it yourself? and I ran into something that h

[sage-support] Re: ultraspherical (Gegenbauer polynomials)

2011-07-13 Thread Steven Pollack
So, for anyone interested, I was able to *sort-of* solve the Gegenbauer polynomial problem. Using a lambda-function: C = lambda (n, Lambda, x): sum( [(2*x)^(n-2*m)*(-1)^(m)*rising_factorial(Lambda,n-m)/(factorial(m)*factorial(n-2*m)) for m in [0..floor(n/2)]] ) (the definition is taken from

[sage-support] Polynomials Mod 7

2011-07-13 Thread Mel
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[] sage: ideal = -6*x - y sage: ideal = IntegerPo

Re: [sage-support] Graphics() objects and a histogram

2011-07-13 Thread Tom Boothby
Sorry, I didn't read carefully; you do seem to know about the timeseries code. I'm assuming that the xmax is the midpoint of the rightmost bin + half the bin width; are you doing something else? It's hard to guess at what's going wrong if you don't post code. FWIW, I'd prefer that "plot_histogram

Re: [sage-support] Graphics() objects and a histogram

2011-07-13 Thread Tom Boothby
Try the following: TimeSeries(s).plot_histogram() On Wed, Jul 13, 2011 at 3:29 PM, David Monarres wrote: > Hello all, > Today I was working on a top-level histogram plotting function by exposing > matplotlib's hist as a Graphics object and I ran into something that has > stumped me. This is no

[sage-support] Re: Product probability space

2011-07-13 Thread David Monarres
Does this work for you? sage: S = ['h','t'] sage: P = dict(zip(S,[1/2,1/2])) sage: P {'h': 1/2, 't': 1/2} sage: O = DiscreteProbabilitySpace(S,P) sage: dict( [ ((s1,s2),P[s1]*P[s2]) for s1 in S for s2 in S] ) {('h', 't'): 1/4, ('t', 't'): 1/4, ('h', 'h'): 1/4, ('t', 'h'): 1/4} It doesn't real

[sage-support] Graphics() objects and a histogram

2011-07-13 Thread David Monarres
Hello all, Today I was working on a top-level histogram plotting function by exposing matplotlib's hist as a Graphics object and I ran into something that has stumped me. This is not surprising since I know very little about matplotlib and am not all that experienced with programming in general

[sage-support] Re: psi function.

2011-07-13 Thread robin
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 number of calls to psi()? This would just be an integer, wit

[sage-support] Problem with 'desolve_system'

2011-07-13 Thread Ondra Pelech
Hello, I'm having troubles with using desolve_system on differential equations system. There is an Error executing code in Maxima. I really don't know what might be going on, please help or suggest how to bypass this. Thanks a lot Ondra the whole notebook is here: https://molly.kyberia.cz:8000/

[sage-support] Very slow matrix calculations in SAGE

2011-07-13 Thread hdevalence
Hello, I'm having some trouble with some matrix calculations in SAGE. I'd like to find the kernel of some matrices, but I think I'm doing something wrong, because it's very slow. For example: sage: M = matrix(RDF, 200,400, lambda i,j: i+j) sage: %time M.right_kernel() CPU times: user 379.39 s, sy

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

2011-07-13 Thread Michael Orlitzky
On 07/12/11 22:07, robin wrote: > Hi again > > [replying to self] > > I didn't make myself clear here. What I meant to ask was, I think, > > "Look, sage doesn't seem to know this fact about psi(). Does sage > store a list of known facts about the psi function anywhere? > > Because, if it does

[sage-support] Re: Cannot sign out

2011-07-13 Thread Andrey Novoseltsev
P.S. I tried removing the cookie of the notebook site - this disconnects me from the notebook server, but after the first login I cannot logout anymore. -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@go

[sage-support] Cannot sign out

2011-07-13 Thread Andrey Novoseltsev
Hello, I have the following problem on my machine: - connect to a new secure Sage notebook - log in - log out - log in - now it is not possible to log out, I am just thrown to the home page (and it does work, i.e. I still have access to all the worksheets). Clearing the history of the browser hel

[sage-support] Implementation of Lenstra-Lenstra-Lovesz Algorithm

2011-07-13 Thread Zimmermann Paul
Hi, > I have written following Lattice Reduction Algorithm. However, it does not > work properly (does not matche with the LLL algorithm > implemented in Sage). It will be great for me if any one check the program. the output of the LLL algorithm is not unique. You have to check that the o