Re: [sage-devel] Re: should LPs default to assuming nonnegative variables in Sage?

On Sat, Dec 14, 2013 at 8:32 AM, Nathann Cohen wrote: > > I frequently use the IP/LP functionality in Sage for problems in graph > > theory. > > Hmmm.. I'm *very* glad to learn this :-) > And I appreciate all the work that you and the other Sage developers have put into making the IP/LP functiona

Re: [sage-devel] Re: should LPs default to assuming nonnegative variables in Sage?

I frequently use the IP/LP functionality in Sage for problems in graph theory. I'm now used to the assumption that most solvers make about variables being nonnegative, but I find it nonobvious and it has tripped me up several times in the past. I think that making no assumption about variables bu

[sage-devel] Open position in Scientific Computing and Computational Mathematics at the University of Nebraska-Lincoln

py to answer any questions you may have about the position or UNL; please email me directly. Best wishes, Stephen Hartke Department of Mathematics University of Nebraska-Lincoln -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To post to t

Re: [sage-devel] Re: Touch Interacts on iOS

> > On 1/22/12 12:56 PM, Stephen Hartke wrote: > >> Cutting and pasting on an Android phone does not work well (I had to >> switch to plain text to paste into the code box).. Will there > > eventually be an option to "preload" code into the single cell server

Re: [sage-devel] Touch Interacts on iOS

On Sat, Jan 21, 2012 at 12:35 PM, Jason Grout wrote: > Can people test this functionality before we try to add it to the sage > notebook? If you have an iOS or Android device, create an interact at > aleph.sagemath.org and try manipulating the controls. > The sliders on the n^2 example work grea

Re: [sage-devel] Assignment of matrix to a matrix slice fails in the 1x1 case

On Sun, Feb 27, 2011 at 10:32 PM, D. S. McNeil wrote: > I think this has changed very recently. Your code seems to work in > 4.6.2.rc0, but not in 4.6.1. Doug, Thanks for the response! I am using Sage 4.6. This bug was reported in trac #9747

[sage-devel] Re: Assignment of matrix to a matrix slice fails in the 1x1 case

The slice assignment does work as expected for numpy arrays: import numpy k=5 A=numpy.array([range(i,i+k) for i in range(k)]) for i in range(A.shape[1]): print i, try: A[0:i,0:i]=A[0:i,0:i] print except TypeError as e: print "This slice assignment failed:",e

[sage-devel] Assignment of matrix to a matrix slice fails in the 1x1 case

Assignment of a matrix to a matrix slice works as expected except for when the slice is 1x1; in that case, Sage expects a scalar instead of a 1x1 matrix. The following code demonstrates the problem: k=5 A=matrix(RDF,k,k,range(k^2)) for i in range(A.ncols()): print i, try: A[0:i,0:

[sage-devel] Re: Linear Programming and MIP... Let's start something huge !

On Mon, Jun 29, 2009 at 10:18 AM, Nathann Cohen wrote: > > It may be a good idea to interface to OSI in order to avoid having to > interface to both CPLEX and COIN-OR, but for license reasons we can > not use OSI to interface to GLPK as OSI is GPL-Uncompatible and the > only reason we want glpk in

[sage-devel] Re: Determining platform when building an spkg

On Sat, Jun 13, 2009 at 3:13 AM, William Stein wrote: > 2009/6/12 Stephen Hartke : > > What is the recommended way of determining which platform Sage is running > on? > > Look at the output of the uname command. You can find examples of > this sort of thing happening

[sage-devel] Determining platform when building an spkg

Now that the semester is over, I'm trying to finish the spkg for lp_solve. lp_solve does not use autoconf and make, but rather has its own specialized build scripts for different platforms (mainly Windows, Mac OS X, and Linux/UNIX). What is the recommended way of determining which platform Sage is

[sage-devel] Re: sage-4.0

On Sat, May 30, 2009 at 9:34 AM, William Stein wrote: > I have release sage-4.0. It's now available at > http://sagemath.org/src/. Binaries will follow in a day. > Sage 4.0 compiled cleanly from source on Fedora 8 x86_64 Linux, but I get a segfault with the following commands: theta1,theta2=

[sage-devel] Re: linear programming via lp_solve in sage

I have updated the lp_solve spkg to the latest version, lp_solve 5.5.0.14. I have also included the documentation files, which I install into $SAGE_LOCAL/share/doc/lp_solve-5.5.014. Is this the correct location for documentation files? The updated spkg is located at http://www.math.unl.edu/~shart

[sage-devel] Re: JavaScript Graph editor

On Thu, Apr 30, 2009 at 2:05 AM, Rado wrote: > Here is the result: > http://www.math.uiuc.edu/~rkirov2/processing/grapheditor.html > Rado, This is really cool! It would be awesome if this was incorporated into Sage. Best wishes,

[sage-devel] Re: linear programming via lp_solve in sage

On Sun, Apr 12, 2009 at 8:45 AM, David Joyner wrote: > > On Sat, Apr 11, 2009 at 11:25 PM, Stephen Hartke wrote: > > I have made an spkg for lp_solve and posted to sage-devel a message in > > September 2008 about including it into Sage. I did not receive any > positive >

[sage-devel] Re: linear programming via lp_solve in sage

I have made an spkg for lp_solve and posted to sage-devel a message in September 2008 about including it into Sage. I did not receive any positive responses. The spkg and a demo file domination.py can be downloaded at: http://www.math.unl.edu/~shartke2/files/

[sage-devel] lp_solve spkg

lp_solve is a free linear programming and integer programming solver. The library is written in C, but the developers provide bindings to several languages, including Python. I have created an spkg for installing lp_solve into Sage. The spkg is located at: http://www.math.unl.edu/~shartke2/files

[sage-devel] Re: python binding for nauty in optional spkg

On Thu, Aug 28, 2008 at 5:13 PM, mabshoff <[EMAIL PROTECTED]> wrote: > On Aug 28, 2:54 pm, Jason Grout <[EMAIL PROTECTED]> wrote: > > > The Python extension is linked against nauty object files, and gcc > > > complains these should be compiled with the flag "-fPIC" to make > > > relocatable code.

[sage-devel] Re: python binding for nauty in optional spkg

On Thu, Aug 28, 2008 at 4:59 PM, mabshoff <[EMAIL PROTECTED]> wrote: > > The Python extension is linked against nauty object files, and gcc > complains > > these should be compiled with the flag "-fPIC" to make relocatable code. > > nauty does not have this flag normally, so I modified the makefil

[sage-devel] python binding for nauty in optional spkg

I've added my Python binding for nauty into Jason Grout's optional nauty spkg. (Jason: I hope that's okay. Since the extension needs to include nauty and link against it, it seems simplest to include it in one package.) It can be downloaded at http://www.math.unl.edu/~shartke2/files/nauty-24b7.spk

[sage-devel] Re: enumerating colorings of graphs

On Wed, Apr 23, 2008 at 6:20 PM, Jason Grout <[EMAIL PROTECTED]> wrote: > I have a need to enumerate all possible black and white colorings of a > graph, up to (colored) isomorphism. Is there a way to use some of the > NICE code to make this fast? It seems like I read somewhere that Robert > was

[sage-devel] Re: Bad example with NICE graph isomorphism

: > > > : print "NICE says the graphs are isomorphic" > > > : else: > > > : print "NICE says the graphs are NOT isomorphic" > > > : > > > NICE says the graphs are isomorphic > > > > Hi Ste

[sage-devel] Bad example with NICE graph isomorphism

Attached is an example where NICE does not correctly determine the isomorphism between two graphs. I tested this with Sage 2.11. I have not had an opportunity to examine the NICE code, so I'm not sure where the problem is. I do not currently have a Trac account, so I am sending the example here.