> On Tuesday, 1 September 2015 07:00:39 UTC-7, Craig E Larson wrote:
>> I see that there are methods for saving a LP as and LP or MPS file in
>> Sage. Is it possible to *load* an LP from one of these file types? The
>> online help that I've found doesn't mention this or give examples of how to
>>
Adding row constraints one at a time is slow because of the internal data
structures that simplex solvers use. In large LPs/IPs, the constraint
matrix is almost always sparse, and so allocating an entire dense matrix
doesn't make sense. Instead, a packed sparse matrix is used. Because of
the
On Tue, Jan 7, 2014 at 1:58 AM, Nathann Cohen nathann.co...@gmail.comwrote:
Something is indeed wrong, and I have experienced similar problems in
the past. What version of CPLEX and which version of Sage are you using? I
am using IBM ILOG CPLEX 12.5.1.0, and Sage 5.12 on Fedora Linux 19 and
Sorry for the delay in responding, but I was traveling over the holidays.
Happy New Year!
On Sun, Dec 15, 2013 at 5:18 AM, Nathann Cohen nathann.co...@gmail.comwrote:
{0: 2.0, 1: 0.0}
Note that x[0] has the solution 2, which shouldn't happen for a binary
variable.
When I ran the example
It seems that Integer Programs solved with CPLEX sometimes have the wrong
bounds on binary variables. For instance,
p=MixedIntegerLinearProgram(solver=CPLEX)
x=p.new_variable(dim=1) #,binary=True)
p.add_constraint(x[0]+x[1]==2)
p.set_objective(None)
p.set_binary(x)
p.show()
p.solve()
print
Doug, thanks for the smaller example! The bug may be dependent on the
labels of the vertices, as all the similar small examples I tried to create
worked successfully with edge_cut.
I've created a trac request: ticket
12797http://trac.sagemath.org/sage_trac/ticket/12797
.
Best wishes,
Stephen
While generating subtour elimination constraints for a traveling salesman
problem, I bound a bug in the edge_cut method for undirected weighted
graphs. Specifically, when using the Ford-Fulkerson method, the value of
the minimum cut is correct, but sometimes the returned edge cut does not
have
Ivan and Karl,
Thanks for pointing out Huss and Marik's sws2tex! That's mostly what I
want. As discussed on ask.sagemath.org, there are some problems:
with solutions: turning off syntax highlighting, turning off the attach
file, saving the TeX file
no (yet!) solutions: aligns of equations are
I've been writing a series of handouts for my class. When writing them, I
like to initially use the Sage notebook as it allows me to quickly and
easily experiment with different examples, while still writing most of the
explanations. However, for various reasons I'd like to be able to post pdf
On 2/8/12 10:30 PM, Stephen Hartke wrote:
I could not immediately find a feature to export to SageTeX. If such a
feature does not already exist, how hard would it be to implement it?
On Wed, Feb 8, 2012 at 10:37 PM, Jason Grout jason-s...@creativetrax.comwrote:
I don't think it exists
On Sun, Mar 13, 2011 at 12:08 AM, pong wypon...@gmail.com wrote:
A quick question. How to use sagetex to display a graph (edges and
vertices) produced by sage without saving it first manually then
\includegraphics.
Plotting graphs works by calling sageplot on the graph's plot:
When using the Print feature on a worksheet in the notebook, a new webpage
is generated for easy printing of the new worksheet. In the to print
worksheet, the word wrap of the output text is fixed at something less than
70, resulting in short output lines when printed. This wastes a lot of the
On Wed, Nov 24, 2010 at 2:20 PM, Minh Nguyen nguyenmi...@gmail.com wrote:
But I can't figure out how to get G.show() to display the edge weights.
You can just call G.show(edge_labels=True), which displays the vertex names
(by default) and the edge labels. Of course, the layout is whatever the
On Sun, Jul 26, 2009 at 12:31 AM, Carlo Hamalainen
carlo.hamalai...@gmail.com wrote:
On Sat, Jul 25, 2009 at 5:08 PM, Stephen Hartkehar...@gmail.com wrote:
Might this be related to how binomial is evaluated using GiNaC?
Valgrind says yes:
==26568== 4 bytes in 1 blocks are definitely lost
The following code ends up using a lot of memory:
print get_memory_usage()
for i in range(10):
b=binomial(5,2)
print get_memory_usage()
Output:
133.48828125
135.015625
So 1.5 extra megabytes is used after the 100,000 calls of binomial. If
repeated calls to binomial are made, eventually
On Sat, Jul 25, 2009 at 1:54 PM, Justin C. Walker jus...@mac.com wrote:
I just tried this on 4.0.2 and 4.1 (on Mac OS X, 10.5.7), and got the
same values before and after the loop, so something else must be
involved.
Justin,
Thanks for your response! Did you run it from the command line or
On Sat, Jul 25, 2009 at 6:04 PM, Justin C. Walker jus...@mac.com wrote:
I noticed that in the notebook, the code does create a problem,
^ not??
but random values do.
Yes, I missed a not.
Yup. I now see what you see: memory usage increases
On Wed, Feb 25, 2009 at 6:52 AM, Marco Streng marco.str...@gmail.comwrote:
I'm doing a long computation in Sage and I'd like to be able to print
some status information to the screen, such as the number of database
entries that I have tested, or the total time spent on different parts
of an
On Mon, Feb 2, 2009 at 10:04 AM, Jason Grout jason-s...@creativetrax.comwrote:
kcrisman wrote:
I don't believe that turning a notebook worksheet into a pdf is
implemented (and thanks to Dan D. for SageTeX, which unfortunately
I have been printing worksheets to PDF files using my web
I have created a spkg to install lp_solve into Sage; it can be obtained at:
http://www.math.unl.edu/~shartke2/files/lp_solve-5.5.0.13.spkg
I have posted to sage-devel suggesting this spkg for inclusion into Sage.
lp_solve includes a linear programming solver (simplex based) and an integer
Hi! I have some questions about matrices and solving linear systems of
equations. These issues arose out of my using Sage for examples in my
Linear Optimization class (it's great for demonstrating how the simplex
algorithm works!) and for research I'm doing involving finite fields.
If I have a
[EMAIL PROTECTED] wrote:
On Fri, Apr 25, 2008 at 6:56 AM, Stephen Hartke [EMAIL PROTECTED] wrote:
I currently have some Sage code in a file called main.sage. I call this
from
the Sage command line interpreter with load main.sage. After
profiling my
code, I moved a few functions
I currently have some Sage code in a file called main.sage. I call this from
the Sage command line interpreter with load main.sage. After profiling my
code, I moved a few functions into a cfuncs.spyx which I call with a load
cfuncs.spyx command in main.sage. This works great, and cfuncs.spyx is
23 matches
Mail list logo
