Re: [sage-devel] Re: graph theory: clarify the purpose of keyword "directed" in degree() of CGraphBackend

Hmmm I am sorry but for once, I do not think this is really a matter of mathematical justification For undirected graph, we settled recently on saying that the degree of a single vertex with a loop is equal to 2, because we do not want the inequality (sum of the degrees) = 2* (number of ed

Re: [sage-devel] Sage 4.4.alpha1 released

Hi John, On Thu, Apr 22, 2010 at 6:33 PM, John Cremona wrote: > PS No-one else is posting build & test reports to sage-devel. Did I > miss something? SHould this be going to sage-release? I think people have started to post doctest/build failures and successes to sage-release. A lot of repl

[sage-devel] Re: graph theory: clarify the purpose of keyword "directed" in degree() of CGraphBackend

On 23 Apr., 04:28, Minh Nguyen wrote: > [...] The above demonstrates a bug in > the implementation of degree() as it doesn't handle self-loops > consistently. I understand that the total degree of any graph is twice > the number of edges. If we only consider directed or undirected, cyclic or acyc

[sage-devel] Notebook Cells

Can someone give me an explanation of how to embed objects in cells. For example, how does plot work? If I want to make a function that embeds an image in a notebook cell, how would I do this? What I want is to make Python code that communicates with a Java GUI in a notebook cell. If you click t

[sage-devel] Re: erf + solve

Addendum: I suppose a general query would be how do we incorporate new knowledge into Sage (narrowing this down to things like (a) closed form expressions of integrals (b) well known expressions of finite or infinite sums (c) well known solutions of equations such as the previous message Is it a m

Re: [sage-devel] Re: graph theory: clarify the purpose of keyword "directed" in degree() of CGraphBackend

Hi Leif, On Fri, Apr 23, 2010 at 7:47 AM, Nathan O'Treally wrote: > And for the single-node undirected circular graph: there's only one > edge, so degree can't be larger than 1. I think the method degree() of CGraphBackend has a bug similar to that which is tracked at ticket #8395 [1]. For a

[sage-devel] erf + solve

Question 1: Is it possible (and reasonable) to have the error function, erf, return 0 for "erf(0)"? Currently it returns the expression: erf(0) Question 2 (related): The standard normal (or Gaussian) curve has half its (unit) area to the left (and right) of x==0 as we see here... sage: gaussian =

[sage-devel] Re: spammer on Sage trac server

On 04/22/2010 08:27 PM, Minh Nguyen wrote: Hi folks, We have a spammer on Sage's trac server. The spammer goes by the following identity: * username: mike3050 * name: Mike Smith * email: j...@zolpo.com That spammer has edited the description of ticket #8405 [1] with spam content. I have delete

[sage-devel] spammer on Sage trac server

Hi folks, We have a spammer on Sage's trac server. The spammer goes by the following identity: * username: mike3050 * name: Mike Smith * email: j...@zolpo.com That spammer has edited the description of ticket #8405 [1] with spam content. I have deleted that spammer's account on trac and have mov

[sage-devel] Re: Sage 4.4.alpha0 fails to build on t2.math (SPARC Solaris 10)

On 18 Apr., 20:54, "Dr. David Kirkby" wrote: > I do wonder if the whole of the Sage library should be built C99. I'm not sure > how it works if some parts are, and other parts are not. I could imagine that > might have the potential to have some undesirable side effects. Perhaps it is > better to

Re: [sage-devel] Re: A better ``prun`` example for the tutorial?

Hi Simon, > > I had one this morning but it is now much faster :-) At least in the > > combinat > > branch. I should be soon much faster in sage too: > > > > sage: P=Posets.BooleanLattice(4) > > sage: %prun [x <= y for x in P for y in P] > >          405879 function calls in 2.478 CPU secon

[sage-devel] Re: A better ``prun`` example for the tutorial?

Hi Florent! On 22 Apr., 23:51, Florent Hivert wrote: > I had one this morning but it is now much faster :-) At least in the combinat > branch. I should be soon much faster in sage too: > > sage: P=Posets.BooleanLattice(4) > sage: %prun [x <= y for x in P for y in P] >          405879 function cal

Re: [sage-devel] get @parallel to nice the subprocesses

On Thu, 22 Apr 2010 06:39:15 -0700, William Stein wrote: > > Not that I know of, unless you just start the parent process with low > priority. Can you just start the parent process with low priority, or is > there some reason it has to have high priority? > No good reason. I just keep forgett

Re: [sage-devel] A better ``prun`` example for the tutorial?

Hi ! > So, apparently this example is stone-age (version 1.0), it suggests > that matrix multiplication is slow in Sage, but actually this example > is immediate (rather than 1.1 CPU seconds!) today. > > Do you have a nice example of a computation that is slow in one > implementation, and "

[sage-devel] Re: graph theory: clarify the purpose of keyword "directed" in degree() of CGraphBackend

On 22 Apr., 10:52, Nathann Cohen wrote: > In Sage, the "degree" of a vertex in a directed graph is the degree of > the same vertex in the undirected version of the graph. It is the > number of edges "touching" this vertex. If you just want the out- > degree (number of edges leaving the vertex), th

[sage-devel] Re: Translation of "coercion"

On 22 Apr., 23:31, Simon King wrote: > PS: > > On 22 Apr., 23:13, Simon King wrote: > > > > > I like Umwandlung! It sounds rather natural to say "Es gibt eine > > kanonische Umwandlung von ZZ nach GF(5)". > > That said: How would one express the difference between "conversion" > and "canonical

[sage-devel] Re: Translation of "coercion"

PS: On 22 Apr., 23:13, Simon King wrote: > > I like Umwandlung! It sounds rather natural to say "Es gibt eine > kanonische Umwandlung von ZZ nach GF(5)". That said: How would one express the difference between "conversion" and "canonical coercion"? Example: sage: R1. = ZZ[] sage: R2 = ZZ['d'

[sage-devel] Re: Translation of "coercion"

Hi! On 22 Apr., 22:35, "Nathan O'Treally" wrote: > Context? (just) Type theory? More than type, I think, but it certainly goes in that direction. E.g., you want to compare an element x of QQ with an element y of ZZ['t'] -- then Sage finds that there are both canonical coercions from QQ to QQ['t'

[sage-devel] Re: Translation of "coercion"

On 21 Apr., 21:37, Simon King wrote: > I am trying to translate "coercion" to German. In dictionaries and > Wikipedia, I only found the legal notion of a coercion, but I doubt > that "kanonische Nötigung" and "Nötigungsmodell" are good translations > for "canonical coercion" and "coercion model"

Re: [sage-devel] get @parallel to nice the subprocesses

On Thu, Apr 22, 2010 at 8:24 PM, Alex Ghitza wrote: > > Hi, > > I'm currently using the @parallel decorator in a more serious way to run > a bunch of computations on several cores. It's working great! > > There is one thing that I'd like to be able to do, and my poking around > has not resulted

Re: [sage-devel] get @parallel to nice the subprocesses

On Thu, Apr 22, 2010 at 5:24 AM, Alex Ghitza wrote: > > Hi, > > I'm currently using the @parallel decorator in a more serious way to run > a bunch of computations on several cores. It's working great! > > There is one thing that I'd like to be able to do, and my poking around > has not resulted

[sage-devel] A better ``prun`` example for the tutorial?

Hi! In the section on "Profiling" at http://www.sagemath.org/doc/tutorial/programming.html#profiling, I read: """ To profile (the currently slow! - as of version 1.0) matrix multiplication over finite fields, for example, do: sage: k,a = GF(2**8, 'a').objgen() sage: A = Matrix(k,10,10,[k.random

[sage-devel] get @parallel to nice the subprocesses

Hi, I'm currently using the @parallel decorator in a more serious way to run a bunch of computations on several cores. It's working great! There is one thing that I'd like to be able to do, and my poking around has not resulted in an answer. I want the subprocesses that are started to have low

Re: [sage-devel] Re: Sage 4.4.alpha0 fails to build on t2.math (SPARC Solaris 10)

Hi John, On Thu, Apr 22, 2010 at 4:22 AM, John H Palmieri wrote: > Please see > > > > for a patch. After a fail build, I applied the patch and resumed my build. A few hours later, the build finished. It looks like the build was successful this

[sage-devel] Re: graph theory: clarify the purpose of keyword "directed" in degree() of CGraphBackend

In Sage, the "degree" of a vertex in a directed graph is the degree of the same vertex in the undirected version of the graph. It is the number of edges "touching" this vertex. If you just want the out- degree (number of edges leaving the vertex), then it is out_degree (resp in-degree, in_degree).

Re: [sage-devel] Sage 4.4.alpha1 released

On 32-bit Suse: cat /proc/version Linux version 2.6.27.45-0.1-pae (ge...@buildhost) (gcc version 4.3.2 [gcc-4_3-branch revision 141291] (SUSE Linux) ) #1 SMP 2010-02-22 16:49:47 +0100 I get this test failure after a successful build from scratch: sage -t -long "devel/sage/sage/graphs/planarity.p

[sage-devel] graph theory: clarify the purpose of keyword "directed" in degree() of CGraphBackend

Hi folks, I'm trying to do some clean-ups [1] of the C graph module sage/graphs/base/c_graph.pyx I'm almost done and am about to finish off a patch. However, I need some clarification for the method degree() of the class CGraphBackend. As of Sage 4.4.alpha1, the definition of this method is as f