On Sat, 14 May 2005 [EMAIL PROTECTED] wrote:
gcc -g -O2 -o glpsol glpsol.o ../src/libglpk.a
../src/libglpk.a(glpmpl3.o): In function `glp_mpl_fp_power':
/home/harun/optimize/glpk-4.2/src/glpmpl3.c:184: undefined reference to `log'
/home/harun/optimize/glpk-4.2/src/glpmpl3.c:186: undefined
On Thu, 15 Sep 2005, Lingzi Li wrote:
I am using GLPKMEX to develop my project now. It is a branch-and-price
problem, and I use GLPK to solve Lagrangian relaxation's master and sub
problems. The subproblem is like the following:
min y - sum(ui*xi)
s.t. sum(wi*xi) = c*y
xi + xj = 1
On Mon, 30 Jan 2006 [EMAIL PROTECTED] wrote:
This question probably reveals my poor grasp of MIP solving, but here
goes:
I'm trying to use glpsol in MIP mode as part of a software build process,
specifically a locate step. The problem being solved is to assign various
code sections into
On Tue, 14 Nov 2006, Andrew Makhorin wrote:
There is a dilemma, because I do not think that mixing modeling
and programming capabilities within model description (as in
AMPL) is a good idea; on the other hand I would like to keep
compatibility between GNU MathProg and AMPL. Probably, there
On Wed, 15 Nov 2006, Robert Fourer wrote:
How would what you want differ from the ability to write a script such as the
one copied below? It's a simple script for sensitivity analysis -- there are
much more complicated examples -- but it serves as an example of how a
modeling
language's
On Thu, 22 Feb 2007, Salim Fadhley wrote:
For an experimental project my objective is to count the number of solutions
andnot optimize for a particular constraint. The puzzle is a pretty basic one
for
now:
var a1 =0; /* 200 */
var b1 =0; /* 100 */
var c1 =0; /* 50 */
var d1 =0; /*
On Sun, 25 Feb 2007, Andrew Makhorin wrote:
I'd assumed he'd meant integral solutions.
I counted just over 47 billion (American) of them.
47067239986 :) Right?
Yes.
--
Mike [EMAIL PROTECTED]
Finally, mount the partition, not the virgin. -- Charles Curley
On Thu, 28 Jun 2007, pacho wrote:
I have used the example fot shortest path, adapt it to my graph, run glpsol
and .. and . and .
And after 51 minutes I have got solution . but it ist too much for me .
Is there a possibility to make it faster? Some king of precompile? Table is
always the
On Thu, 28 Jun 2007, pacho wrote:
There are like 180 thousands of nodes in the net :-)
Best solution for me, is to have it counted before www timeout :-)
If you also have 10 billion arcs, 51 minutes isn't all that bad.
For a single shortest path problem, there are O(m + n log(n)) alogrithms,
On Tue, 2 Oct 2007, Andrew Makhorin wrote:
But how do I set a binary variable's value depending on a linear
inequality. I.e. in CPLEX I would use something like: b_0 = 1 - a_0
x_0 + a_1 x_1 + ... + a_n x_n c with b_0 a binary variable, a_0 ...
a_n, c constants and x_0 ... x_n either
On Wed, 7 Nov 2007, Gabor Retvari wrote:
I would like to ask your help regarding a strange linear feasiility problem I
have: I am serching for some [x,y] vector in a (polyhedral) set 'P', so
that 'x' is not a scalar multiple of 'y'. That is, I want to find
[x,y] \in P = {[x,y]: Ax + By \le
On Wed, 7 Nov 2007, Gabor Retvari wrote:
On Wednesday 07 November 2007, Michael Hennebry wrote:
On Wed, 7 Nov 2007, Gabor Retvari wrote:
I would like to ask your help regarding a strange linear feasiility
problem I have: I am serching for some [x,y] vector in a (polyhedral) set
'P
On Thu, 29 Nov 2007, Leandro Barcelos wrote:
On Nov 29, 2007 3:15 PM, ican.ozgur [EMAIL PROTECTED] wrote:
Hi GLPK'ers.
I have a binary variable say, x_dh, having day and hour indices .If x_dh
is
1 i want it to be also 1 for the consecutive 2 hours. Do you have any idea
on how to
On Fri, 30 Nov 2007, ican.ozgur wrote:
On Friday 30 November 2007 07:32:15 Oscar Gustafsson wrote:
On Thu, 29 Nov 2007, Michael Hennebry wrote:
Mathematically correct, but one should go for a tighter linear
relaxation. x[d,h]=x[d,h+1]
x[d,h]=x[d,h+2]
With this formulation
On Mon, 3 Dec 2007, ican.ozgur wrote:
On Friday 30 November 2007 18:37:31 Michael Hennebry wrote:
Probably what you want are binaries based on start times.
You don't need to explicitly mark every period of a class.
OK i understand it. But the question now is how to implement a constraint
On Mon, 14 Jan 2008, Ali Baharev wrote:
I faced the following problem. I repeatedly call glp_simplex on the
same lp object (only continuous variables) after manipulating the
objective function. The objective function value i get seems to be a
bit inaccurate (say the third digit seems to be
On Tue, 15 Jan 2008, Ali Baharev wrote:
I do not know the solution with guaranteed accuracy, it would require
a self-validating method such as interval arithmetic. I only suspect
that the solver has numerical problems as i have inconsistent results.
An error estimate on the result of the
On Tue, 15 Jan 2008, Ali Baharev wrote:
I did try the exact solver but it is very-very slow, as i expected.
My LP problems are generated by successive linearization of a
nonlinear problem, and i need to automate the solution process. So my
problem is not only for this particular LP problem,
On Wed, 16 Jan 2008, Dan Tulk wrote:
Thank you all for your help. I wonder if it makes a difference when I explain
the whole problem. I apologise for not doing so initially. What I'm *really*
trying to solve is:
max f(x)
s.t.
f(x)/abs(g(x)) = m
What is a good way to do this with a
On Tue, 15 Jan 2008, Michael Hennebry wrote:
On Wed, 16 Jan 2008, Dan Tulk wrote:
Thank you all for your help. I wonder if it makes a difference when I
explain the whole problem. I apologise for not doing so initially. What I'm
*really* trying to solve is:
max f(x)
s.t.
f(x
On Wed, 16 Jan 2008, Andrew Makhorin wrote:
I have a large model which I want to run on a machine with small amount
of memory (80M), which leads to xmalloc errors.
Is there a way of capping memory consumption (i.e. by caching to disk)? I
realize this would impact performance.
No, it is
On Mon, 21 Jan 2008, Marc Lanctot wrote:
Suppose I use GLPK's implementation of the Simplex algorithm to solve a
linear program built from two-player equilibria equations for a
particular matrix game, and get back a mixed strategy (a probability
dist. which does not only have 1 and 0
On Fri, 8 Feb 2008, Joey Rios wrote:
For my particular problem, I have a method for obtaining a feasible,
sub-optimal solution using GLPK. I do this by creating a subproblem that
optimizes the 'tricky' parts of the problem. It's usually within 10-20% of
optimal and can be found 10-20X
On Sat, 9 Feb 2008, Daniel Reckhard wrote:
after specifying a 3-dimensional array of vars [1] in my model file I am
surprised to see that this array appears to be unsorted [2]. That is
very annoying as in the C API vars are always referenced by index [3].
So, to calculate a valid index from
On Sat, 9 Feb 2008, Andrew Makhorin wrote:
after specifying a 3-dimensional array of vars [1] in my model file I am
surprised to see that this array appears to be unsorted [2]. That is
very annoying as in the C API vars are always referenced by index [3].
So, to calculate a valid index
On Wed, 13 Feb 2008, glpk xypron wrote:
LP is polynomial, but so far as I know,
no known simplex algorithm is polynomial.
See
Jonathan A. Kelner, Daniel A. Spielman
A Randomized Polynomial-Time Simplex Algorithm for Linear Programming,
2005
On Thu, 14 Feb 2008, Andrew Makhorin wrote:
LP is polynomial, but so far as I know,
no known simplex algorithm is polynomial.
See
Jonathan A. Kelner, Daniel A. Spielman
A Randomized Polynomial-Time Simplex Algorithm for Linear Programming,
2005
On Thu, 13 Mar 2008, vijay patil wrote:
On Sun, Mar 9, 2008 at 4:46 AM, Xypron [EMAIL PROTECTED] wrote:
Where do I want to go to: I would like to use embedding Python scripting
to control the solution process: adding new constraints, changing
variables from float to binary, ... But that
On Thu, 20 Mar 2008, Axel Simon wrote:
I need to use the lpx_exact function and find that the performance on
repeatedly running a 100x10 variable problem is about 70x slower than
using doubles. It turns out that the program spends 40% of it's time
calculating the gcd when canonicalizing
On Tue, 13 May 2008, Xie Zhengwei wrote:
This script tried to get max and min of every variable.
no $lp-std_basis output
10.7272730.00
21.000.00
31.000.00
41.000.00
50.000.00
60.00-1.00
7
On Mon, 9 Jun 2008, Lou Hafer wrote:
This question (`How can I enumerate all vertices using the foo linear
program solver?') comes up a fair bit on the various lists I follow. I
thought
Tell me what you need,
and I'll tell you how to get along without it. -- Dilbert.
Not being as
On Thu, 12 Jun 2008, Fábio Moura wrote:
I had already seen this code. The problem is that the model we are
implementing is a huge one, full of details and lots of different
variables and creating it in memory would be a probably impossible
task in the near future. Is it the only way, though?
On Thu, 12 Jun 2008, Fábio Moura wrote:
I have an application written in C in which the GLPK code is embebded.
The GUI collects the problem data and writes the input file in the
Mathprog format. Then, the program core calls the lpx_read_model
function, which will load both the model and data.
On Fri, 13 Jun 2008, Tor Myklebust wrote:
On Thu, 12 Jun 2008, Michael Hennebry wrote:
Can you use a pipe?
Edit lpx_read_model to use standard input and pipe the information to it.
You might play games with the FILE struct.
Edit lpx_read_model to edit the FILE struct after it opens
On Fri, 13 Jun 2008, Robbie Morrison wrote:
Michael Hennebry wrote (Fri, 13 Jun 2008 08:10:53 -0500 (CDT))
If he doesn't want to edit lpx_read_model and can make a named pipe,
that would work also.
I would consider a name pipe. You need to look in a book on systems
programming
On Thu, 26 Jun 2008, RC Loh wrote:
According to page 62 of the GUN Linear Programming Kit Reference Manual
Version 4.19, it stated that Most probably this solver can be used for
solving MIP problems with one or two hundreds of integer variables. Did
anyone attempt to execute lpx_integer
On Thu, 26 Jun 2008, RC Loh wrote:
Thank you very much for your response. Yes, my problem is a capacitated
transhipment problem. I do not understand what you mean by look for more
constraints or a better formulation. Can you give me an example where
putting more contraints can reduce the
In a specialized single-commodity network flow solver,
the arithmetic is normally exact even if done in floating point.
That is usually not true with multi-commodity flows.
If glpk floating point gives you the correct basis,
glpk exact should give you the exact answer in fairly short order.
So
On Tue, 29 Jul 2008, Markus Pilz wrote:
Andrew Makhorin wrote:
I think that Markus obtains a solution, where some flows are
non-integral while he expects them to be integral due to network
structure and integral arc capacities (I mean max flow and min cost flow
problems). On the other
On Thu, 31 Jul 2008, Andrew Makhorin wrote:
With the lpx_load_matrix for example, and other rutines from the
API, so I wont have to read the data from a file, I pass in the code,
for example a structure.
If you can compute all lp components, you can pass the data directly to
the solver
On Wed, 10 Dec 2008, Andrew Makhorin wrote:
I think that the real output did not work, because in most
implementations of the C run-time library it is checked if the device
assigned to stdout is a terminal device or not (via isatty), and if so,
stdout is open in non-buffered mode (_IONBF)
On Fri, 19 Dec 2008, Joey Rios wrote:
You are completely correct. Though, I'm finding the relaxed solution right now
via a decomposition method (which is why I have no basis at the end) and I'm
finding it up to 100X faster than glp_simplex would otherwise. Since this is
the case, I'd love
On Fri, 19 Dec 2008, Joey Rios wrote:
Hi Michael,
If the relaxed solution found is known to be basic,
the LP can be greatly reduced for the purpose of finding the basis.
Simply remove every constraint that is known to not be tight.
When you put them back, every added variable will be basic.
On Mon, 29 Dec 2008, Selçuk Cihan wrote:
It calculates amounts by which variable bounds may be changed in the
original problem while the optimal basis remains the same.
i am working with suboptimal solutions, lpx_print_sens_bnds() is of no
use for me i guess, it just tells me that i do not
On Fri, 9 Jan 2009, Selçuk Cihan wrote:
Thanks a lot, i have managed to implement the algorithm using GLPK.
And i have compared my solutions to the output of glp_intopt.
That is good to know.
Would you care to share?
I have similar inclinations, but haven't used GLPK in a while.
An example
On Wed, 14 Jan 2009, Yaron Kretchmer wrote:
If finding the minimal set of conflicting constraints is a well known
problem, are there any solutions provided in GLPK for it? Or is this outside
of the scope of GLPK? And if it is, what other tools could be used to find
out the minimal set?
Solve
On Fri, 9 Jan 2009, Selçuk Cihan wrote:
well, since our grades are already posted for the homework, i will be
glad to share the code.
this is a zip file of 27kb size
http://www.2shared.com/file/4613418/36e26fd8/TabuSearch.html
Thank you for the code.
I noticed that you used the lpx_warm_up
On Tue, 20 Jan 2009, Andrew Makhorin wrote:
[Michael Hennebry]
Thank you for the code.
I noticed that you used the lpx_warm_up function iteratively.
IIRC lpx_warm_up is good for setting an initial basis,
but is rather slow as a pivot mechanism.
I'm pretty sure it will refactor the basis from
On Fri, 30 Jan 2009, Simone Atzeni wrote:
Hi,
I have a problem.
My objective function is (in LaTex):
minimize: \delta + \sum_{\tau=t-k+1}^t \lvert\lvert {\bf a}(t+1) -
{\bf a}(\tau) \rvert\rvert
where:
a(t+1): my variables (a is a vector)
a(\tau): coefficients (a is a verctor of
On Fri, 6 Feb 2009, Andrew Makhorin wrote:
Assuming that x and y are integer (in your case x = A and y = B+3),
the condition x != y is equivalent to |x - y| = 1. To describe the
latter constraint, which is non-linear, it is sufficient to describe
the absolute value. Let |s| = u, where s = x - y
On Thu, 19 Mar 2009, rsymbx wrote:
1) Tom is given a large box which contains 1000 bags of marbles.
2) Inside each bag, there are between 1 and 50 marbles.
3) Within a given bag, there are no duplicate colors of marbles, however
there are duplicate colors of marbles across the bags.
4) The bags
On Mon, 4 May 2009, Michael Hennebry wrote:
If the numbers are really small:
Z = SUM Bz[j, k]*max(j, k)
j,k
X = SUM Bz[j, k]*j
j,k
Y = SUM Bz[j, k]*k
j,k
I'd forgotten to add
1 = SUM Bz[j, k]
j,k
I think that this is *linearly* equivalent to the preceeding,
but it has a lot
On Fri, 8 May 2009, Johannes Waldmann wrote:
Z = SUM Bz[j, k]*max(j, k)
j,k
yes, that's basically a unary encoding of numbers as bit strings.
If I'm taking that route, I can go all the way and use *only* booleans.
Then it's a SAT problem, and there are very good solvers for these,
see
On Tue, 2 Jun 2009, Yaron Kretchmer wrote:
I would like to implement the following condition on two variables:
*) If the amount of variable *a* is greater than 0, then the amount of
variable *b* needs to be equal to that of a.
How much greater?
Absent a finite number, I suspect that there is
On Wed, 10 Jun 2009, Andrew Makhorin wrote:
Crashing is a technique used to produce a good starting basis for the
simplex method. This term is widely used; see for example:
http://people.brunel.ac.uk/~mastjjb/jeb/or/lpadv.html .
Whence the term crashing?
It never did make any sense to me.
--
On Thu, 11 Jun 2009, Joey Rios wrote:
My variables are often part of a convex combination, so the sum of some subset
of them needs to be 1. It seems odd that one of them from this subset would be
basic with a value of zero and another is non-basic with a value of 1. I'm
trying to
One might consider running GLPK in separate processes.
The master could communicate with its slaves through popen or something.
--
Michael henne...@web.cs.ndsu.nodak.edu
Pessimist: The glass is half empty.
Optimist: The glass is half full.
Engineer: The glass is twice as big as it needs to
The reentrancy issue could be obviated by
running GLPK instances in separate processes.
--
Michael henne...@web.cs.ndsu.nodak.edu
Pessimist: The glass is half empty.
Optimist: The glass is half full.
Engineer: The glass is twice as big as it needs to be.
On Thu, 2 Jul 2009, Giampaolo Tomassoni wrote:
-Original Message-
From: help-glpk-bounces+g.tomassoni=libero...@gnu.org [mailto:help-
glpk-bounces+g.tomassoni=libero...@gnu.org] On Behalf Of Michael
Hennebry
Sent: Thursday, July 02, 2009 5:17 PM
To: Nigel Galloway
Cc: Help-glpk@gnu.org
On Thu, 2 Jul 2009, Rios, Joseph L. (ARC-AFO) wrote:
Just to chime in again...
One can run multiple processes on multi-cored CPUs.
Shared memory isn't necessarily all that great a model,
but is difficult to avoid with threads.
Separate processes with explicit message-passing
can be a lot
On Mon, 6 Jul 2009, Rios, Joseph L. (ARC-AFO) wrote:
I'm completely with Giampaolo on this. Indeed, you can launch new processes
for parallelization, but having the ability to multi-thread is quite
important. The application for which I had to create the patch launches
1000's of concurrent
On Wed, 22 Jul 2009, Sebastian Pokutta wrote:
there is a trick in the case of binary program that does the job:
If x* in {0,1}^n is the obtained solution after the first run, add the
inequality:
sum{i in I} x_i + sum{i in [n] \ I} (1-x_i) = 1
where I = { i in [n] | x*_i = 0}.
This
On Wed, 12 Aug 2009, Yaron Kretchmer wrote:
a,b,c are binary variables.
I want c to be 1 if and only if a=b=1. What Big-M forumlation do I need?
c = a, b
c = a + b - 1
c = 0
Note that with a and b binary,
the above four constraints make c binary.
One could, if one wanted, omit c's
On Thu, 13 Aug 2009, Yaron Kretchmer wrote:
I've modeled the resources, and created an array of binary variables which
describe whether a certain resource exists in a certain X/Y location.
I'm having difficulties modeling the paths. My difficulty is this:
- Each path maps to a pattern of
problem) with side constraints.
The side constraints might be to ensure
that the paths connect the right things.
If arcs like R2-R2 are desired,
generating them might be difficult.
On Thu, Aug 13, 2009 at 3:00 PM, Michael Hennebry
henne...@web.cs.ndsu.nodak.edu wrote:
On Thu, 13 Aug 2009, Yaron
On Thu, 20 Aug 2009, Sam Seaver wrote:
I'm using Flux Variability Analysis to understand how a metabolic
network may change under different conditions. I'm using glpk, and
for all of the reactions, I am able to get an objective value. For
some of the reactions, glpk reports that the primal
On Sun, 23 Aug 2009, Ali Baharev wrote:
There is nothing wrong.
It seems to me you have chosen the bounds to be the minimum and
maximum value for a 32-bit signed integer.
But your bounds are converted to double precision variables, and GLPK
checks bounds accordingly, the relative error is
On Thu, 3 Sep 2009, Linder Wolfgang wrote:
I have defined binary decision variables in order to allow production only at
certain levels:
plev are the allowed production levels, exactprod are the binary decision
variables, P is the production
This works very well.
However, I would like
On Fri, 4 Sep 2009, Linder Wolfgang wrote:
Thanks very much for your answer.
I tried with --mipgap 20 but often it still takes too long (the program has a
lot of binary variables for diagnostic reasons, for example to calculate the
cost if a machine has to be started, maximum up and down time
On Mon, 14 Sep 2009, Sylvain Fournier wrote:
Extending the subject, is it possible with GLPK to redirect this output to a
file instead of stdout?
glpsol file.txt
--
Michael henne...@web.cs.ndsu.nodak.edu
Pessimist: The glass is half empty.
Optimist: The glass is half full.
On Wed, 16 Sep 2009, Andrew Makhorin wrote:
I create a problem, then optimize it, and save status for variables and
constraints, and delete the problem.
I create a new problem, early the same as the first one : I only remove
some variables (and so modify/remove some constraints).
Is there a
On Mon, 21 Sep 2009, Sam Seaver wrote:
GLPK does allow one to fix variables.
I suspose it's *possible* that telling it a fixed variable is
double bounded instead of fixed might cause it to do the wrong thing.
Probably the difficulty is elsewhere.
Is your problem almost infeasible?
How do I
On Tue, 22 Sep 2009, Sam Seaver wrote:
Yes, I can say that the problem is almost infeasible. I also removed
the column, and applied its constraints directly to the rows involved,
and got the same almost infeasibility for some of these rows.
As it happens, three of these rows are very highly
This might bounce from the list.
NDSU is mucking with my return address.
Kretchmer wrote:
Thanks Larry. What I was looking for is for a way of forcing the C
variable to equal values per the truth table.
If C was binary I could achieve this by a series of inequalities without
big M, and I'm
do not correspond to a valid constraint.
Note that at the tight points, rounding may produce nonzero values.
The others need testing.
I think the constraints you want are defined by
E, A, F and E, B, G.
On Tue, Oct 13, 2009 at 10:16 AM, Michael Hennebry
henne...@www.cs.ndsu.nodak.edu wrote
On Wed, 14 Oct 2009, Alexander Schnell wrote:
i have found out a formulation for your problem but the linear formulation is
quite long:
the nonlinear formulation is quite short:
c = d*b*(b-a)+ e*a*(a-b).
So now you can substitute the term d*b*(b-a) by the variable x and the term
On Sun, 29 Nov 2009, RC Loh wrote:
However, I was pondering for the last 2 days about your response. It seems to
me that the global bound is not much use for my problem. Because the global
will give an *upper bound* for the reliability and bandwidth which is of no
use. A *lower bound* will
On Thu, 3 Dec 2009, RC Loh wrote:
Hi Andrew, Michael, Jeffrey, Ali,
Thank you very much for all your information and advice.
So from what I gathered from all of you are that:
1) An Integer program can be solved using Interior Point method too. Not
necessary solving an Integer program
On Sun, 3 Jan 2010, François Dionne wrote:
I'm thinking of using glpk to solve a series of integer programming
problems. The most difficult one should have around 2048 structural
variables, which are integers with lower bounds of zero and upper bounds
at most 1024 approximately. There are only
On Mon, 4 Jan 2010, Cheng,Jen-Min wrote:
With MS Visual Studio 2008, unsigned int is four bytes and unsigned
short is two bytes. If the value of the unsigned int t is greater than
maximum unsigned short, how will x[i+j] = (unsigned short)t; be
executed? Thanks.
The manner C prescribes is
On Tue, 5 Jan 2010, Andrew Makhorin wrote:
Run-Time Check Failure #1 - A cast to a smaller data type has
caused a loss of data. If this was intentional, you should mask
the source of the cast with the appropriate bitmask. For
example:
char c = (i 0xFF);
What this does is implementation
On Mon, 1 Feb 2010, Pavel Klinov wrote:
Andrew, Michael, thanks a lot for the replies.
Andrew, this is roughly what I meant by searching around. The only
difference is that I also modify the objective function to maximize
diversity and add another constraint to make sure that all subsequent
On Thu, 4 Feb 2010, Pavel Klinov wrote:
If BC search gets interrupted due to time-out and but then is run
again, does it start from scratch or is it able to continue from where
it stopped? Is there a way for it to store all the internal data
structures and continue?
Basically I want GLPK MIP
On Thu, 11 Feb 2010, Ariel Daliot wrote:
Thanks for the reply.
The trick of using an auxiliary binary variable z:
5 * z = x = 10 * z
to make x become semi-continuous 5=x=10 or x=0, effectively turns a
continuous problem into a mixed integer problem with all its woes.
Any idea how to
On Mon, 5 Apr 2010, hncp wrote:
In my previous post I have been wrong in identifying the constraint. What I
actually need is something like XOR operator, not AND operator, i.e. z[i] =
p[i] xor p[i+1]
There are 8 elements of {0, 1}**3.
In this case, 4 of them need to be eliminated.
Just add 4
On Wed, 14 Apr 2010, Hammond, Paul wrote:
I'm thinking since it is written in C, and C is source compatible with C++,
since C++ does support locking in threads, if one was to treat it as a C++ app
written mostly in C, it may be possible to multi-thread it without a huge
rewrite?
C++
On Wed, 14 Apr 2010, Hammond, Paul wrote:
So I guess I just don't mean thread safe, I mean thread hot, as in I can have
multiple GLPK computations going in separate threads simultaneously which don't
need to synchronize on anything or if they do, it's for a very small part of
the computation
On Fri, 23 Apr 2010, Louis Wasserman wrote:
After several from-scratch attempts, I get the following (probably simple)
error from make LIBS=-lpthread: make[2]: Entering directory
`/home/lowasser/glpk-4.43/examples #39;
/bin/bash ../libtool --tag=CC --mode=link gcc -g
On Mon, 26 Apr 2010, Lifit wrote:
Excellent suggestion.
I followed your advice, translated into LP, and got scip to solve my
problem (with no extra settings) in less than 20min.
I also tried writing out to MPS (both wmps and freemps), but for some
reason scip produced incorrect results.
My
On Fri, 25 Jun 2010, glpk xypron wrote:
see the example below.
if w[s] = 0 then inc[s] = 0 else inc[s] = 1
Your if is modelled as
s.t. indicator{s in S} :
w[s] = M * inc[s];
M should be chosen as small as is possible without restricting
the solution.
Possibly better:
w[s] = M[s] *
On Wed, 21 Jul 2010, Silly Me wrote:
On Wed, 21 Jul 2010, Serveh Shalmashi wrote:
I am using GLPK under octave interface for a mixed integer programming
problem, however when running the solver I am facing the following error:
Assertion failed: a != a
The implication is that a is a NaN
On Mon, 30 Aug 2010, xiaomi wrote:
Is there a totural for how to call GLPK in my own C/C++ programming?
There is example code.
And there is a more serious problem: I saw GLPK uses many memories when
it runs longer. If my own C/C++ programming uses almost all the memories
like open a huge
On Wed, 1 Sep 2010, xiaomi wrote:
I am considering to use the property that the result of GLPK is
non-negative to simulate step function as follows:
for example: step function y=u(5);
minimize y
y=M(x-5) , where M is a large number to simulate sharp slope.
y=1;
It seems to imply that when y=5,
On Wed, 1 Sep 2010, xiaomi wrote:
Thanks, Michael. I am sorry there are several typo in my original statement.
Let me recify it as follows:
for example: step function y=u(5);
maxmize y
y=M(x-5) , where M is a large number to simulate sharp slope.
y=1;
The only wired thing is that when x5, y
On Thu, 9 Sep 2010, JoaoFlavio wrote:
I'm trying to run a .bat file from VBA.
It runs with any application, but not with glpsol.
The code is below:
Sub Run_Glpk()
Dim Address As String
Dim Comando As Variant
Commando
Dim Result As Variant
Address = C:\Solver\SNP_48\
Comand
On Thu, 18 Nov 2010, pradeep wrote:
one stupid way may be is
a+x=b+y
u=x
M*u=x
v=y
M*v=y
u+v=1
c=a+(b-a)v
u,v binary
x,y integer =0
M - large integer
Too complicated, too many integer variables and too big an M.
The following constraints are valid and should be in any method:
c=a
c=b
c
On Wed, 19 Jan 2011, Andrew Makhorin wrote:
Forwarded Message
From: chtimax maxcach...@gmail.com
To: Help-glpk@gnu.org
Subject: Re: [Help-glpk] ANNOUNCEMENT: OptimJ solver link for GLPK/Java
Date: Wed, 19 Jan 2011 05:48:23 -0800 (PST)
Hello Robie and All,
Accept my apologies
On Thu, 27 Jan 2011, Marco Giuntoli wrote:
I have a question to ask: In my problem I am analyzing different scenarios
(independent of each other) and each one must make a MIP optimization. Using
OpenMP directives can not go to every single thread on each scenario because
I glpk return number
On Fri, 18 Feb 2011, Xypron wrote:
In the appendix the shiftcover model is changed to only use binary variables.
This makes excluding possible solutions much easier.
The idea for the conversion is replacing integer variables (crew[s]) by sums
of powers of two times binary variables (sum{i in
On Mon, 21 Feb 2011, glpk xypron wrote:
Hello Michael,
If all variables and constraint coefficients are integer,
a single constraint on the nonbasic variables will exclude the
current solution without excluding any other integer solutions.
How do you define nonbasic variable in a MIP
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