Displaying 20 results from an estimated 2000 matches similar to: "Binary optimization problem in R"
2007 Jul 10
1
error using lp function in linux
Hello all,
I would like to use the lp function (lpSolve package) on a linux system. Using sample code from the lp function help, I can solve the linear program with no errors or problems. However, when I copy the exact same code to R in linux (after loading the lpSolve package), I get the following error:
*** caught segfault ***
address 0x3, cause 'memory not mapped'
Traceback:
1:
2010 Apr 20
2
QCA3 segfault
Hi
I have just dwonloaded QCA3 onto this machine (ubuntu, karmic, amd64) and a
mac. The examples run fine on teh mac, but crashed R on ubuntu. Any help
much apprecia\ted.
Thanks
Richard
------------------------------------------------------------------------------
Terminal log:
> conditions <-
>
2005 Mar 30
1
Problems with lpSolve/Memory ? R crashes
Hello!
I have a curious problem, which I cannot solve.
With my code I solve thousands of small linear programs with the package lpSolve automatically.
But R crashes sometimes (~always, but always on different linear programs) in a strange way.
For illustration, I tried to prepare a simple example, which shows the nature of the problem.
The function aaa (see below) declares some constants (only in
2007 Mar 09
1
lpSolve space problem in R 2.4.1 on Windows XP
Hi.
I am trying to use the linear optimizer from package lpSolve in R 2.4.1 on
Windows XP (Version 5.1). The problem I am trying to solve has 2843
variables (2841 integer, 2 continuous) and 8524 constraints, and I have 2 Gb
of memory. After I load the input data into R, I have at most 1.5 Gb of
memory available. If I start the lp with significantly less memory
available (say 1 Gb), I get
2009 Mar 27
1
asking advice for Integer Programming packages
Dear everyone,
I don't know much about Integer Programming but am afraid I am facing
a problem that can only be solved via Integer Programming. I was
wondering if those of you who have experience with it could recommend
an R package.
I found the following R packages:
Rglpk
glpk
lpSolve
lpSolveAPI
Are there any others?
Are some of them easier to use than others for a beginner?
Any advice
2020 Jan 10
5
copying files to fill flash drives
Back in the days of DOS I had a program that I obtained from somewhere called FILL.
FILL would take the name of a directory and then start writing files from that directory onto a series of floppy disks in such a way that each disk was made as full as possible, but without modifying the files that it was writing.
So you might end up with disk 1 having files A B and D on them since D fitted but C
2011 May 13
6
Powerful PC to run R
Dear all,
I'm currently running R on my laptop -- a Lenovo Thinkpad X201 (Intel Core
i7 CPU, M620, 2.67 Ghz, 8 GB RAM). The problem is that some of my
calculations run for several days sometimes even weeks (mainly simulations
over a large parameter space). Depending on the external conditions, my
laptop sometimes shuts down due to overheating.
I'm now thinking about buying a more
2011 Apr 12
2
Testing equality of coefficients in coxph model
Dear all,
I'm running a coxph model of the form:
coxph(Surv(Start, End, Death.ID) ~ x1 + x2 + a1 + a2 + a3)
Within this model, I would like to compare the influence of x1 and x2 on the
hazard rate.
Specifically I am interested in testing whether the estimated coefficient
for x1 is equal (or not) to the estimated coefficient for x2.
I was thinking of using a Chow-test for this but the Chow
2008 Jul 24
1
Coconut benchmark for R?
Hello All,
Could anybody point me out any port of "Global Optimization Test
Problems" OR "Constraint Satisfaction Test Problems" part of Coconut[%]
benchmark or other such similar benchmarks for R.
[%] Coconut benchmark:
http://www.mat.univie.ac.at/users/neum/public_html/glopt/coconut/Benchmark/Benchmark.html
Cheers!
Isa
[[alternative HTML version
2009 Jul 06
1
R- NLP on R but ....
I'll appreciate the help on the following problem:
I solved many Nonlinear programming problems with nonlinear
constraints....Rdonlp is working well but i am unable to get INTEGER data
with nonlinear constraints in Rdonlp. Is it possible to get Integer Values
of parameters in any package of R with nonlinear constraints.
Rahul
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2009 Mar 16
2
FW: Select a random subset of rows out of matrix
Dear all,
I have a large dataset (N=100,000 with 89 variables per subject). This dataset is stored in a 100.000 x 89 matrix where each row describes one individual and each column one variable.
What is the easiest way of selecting a subset of let's say 1.000 individuals out of that whole matrix?
Thanks,
Michael
Michael Haenlein
Associate Professor of Marketing
ESCP-EAP European School of
2010 Nov 11
2
predict.coxph and predict.survreg
Dear all,
I'm struggling with predicting "expected time until death" for a coxph and
survreg model.
I have two datasets. Dataset 1 includes a certain number of people for which
I know a vector of covariates (age, gender, etc.) and their event times
(i.e., I know whether they have died and when if death occurred prior to the
end of the observation period). Dataset 2 includes another
2014 Mar 15
2
[PATCH pkg-libvirt/libguestfs] Split off ZFS support from libguestfs0.
Hilko,
This is an experimental patch showing how to split libguestfs into
subpackages, so the main libguestfs0 doesn't depend on everything.
Splitting packages only works for packages which are in the appliance
(ie. in appliance/packagelist or supermin.d/packages).
In this patch, only zfs-fuse [which previously caused trouble for
users: https://bugs.launchpad.net/bugs/1053911] has been
2016 Apr 16
1
Social Network Simulation
Dear all,
I am trying to simulate a series of networks that have characteristics
similar to real life social networks. Specifically I am interested in
networks that have (a) a reasonable degree of clustering (as measured by
the transitivity function in igraph) and (b) a reasonable degree of degree
polarization (as measured by the average degree of the top 10% nodes with
highest degree divided by
2013 Jan 22
2
Approximating discrete distribution by continuous distribution
Dear all,
I have a discrete distribution showing how age is distributed across a
population using a certain set of bands:
Age <- matrix(c(74045062, 71978405, 122718362, 40489415), ncol=1,
dimnames=list(c("<18", "18-34", "35-64", "65+"),c()))
Age_dist <- Age/sum(Age)
For example I know that 23.94% of all people are between 0-18 years, 23.28%
2008 Jan 28
1
Package Installation produces "linux/limits.h: No such file or directory" error when installing the lpSolve package
Dear Friends,
I am trying to install a few packages in R and am receiving error messages.
Since the error messages are different, I am posting them separately. The
second error is with the installation of lpSolve.
The core error message is:
========================================================================
In file included from /usr/include/bits/posix1_lim.h:153,
from
2009 Sep 22
2
Semi continous variable- define bounds using lpsolve
How to define bounds for a semi continous variable in lp_solve.
Min 5x1 +9x2 +7.15x3 +0.1x4
subject to
x1+x2+x3+x4=6.7
x1+x4 <= 6.5
And x3 can be 0 or greater than 3.6
hence x3 is a semi continous variable
how to define bounds as well as semicontinous function because using
set.semicont and set. bound simantaneously doesn't seem to work.Thanks in
advance for the help
--
View this
2007 Oct 01
1
lpSolve doesn't compile because of a malloc.h error
Under freebsd 6.2-p7 i386, R 2.5.1,gcc-4.2.2 I'm unable to compile package
lpSolve because:
hpbsd# R CMD INSTALL lpSolve_5.5.8.tar.gz
* Installing to library '/usr/local/lib/R/library'
* Installing *source* package 'lpSolve' ...
** libs
cc -std=gnu99 -I/usr/local/lib/R/include -I/usr/local/lib/R/include -I . -DINTEGERTIME -DPARSER_LP -DBUILDING_FOR_R -DYY_NEVER_INTERACTIVE
2008 Apr 18
1
spdep question - Moran's I
Dear all,
I would like to calculate a Moran's I statistic using the moran function in the spdep package. The problem I'm having deals with how to create the listw object.
My data stems from the area of social network analysis. I have list of poeple and for each pair of them I have a measure of their relationship strength. So my dataset looks like: Jim; Bob; 0.5
This measure of
2011 Mar 26
1
Effect size in multiple regression
Dear all,
is there a convenient way to determine the effect size for a regression
coefficient in a multiple regression model?
I have a model of the form lm(y ~ A*B*C*D) and would like to determine
Cohen's f2 (http://en.wikipedia.org/wiki/Effect_size) for each predictor
without having to do it manually.
Thanks,
Michael
Michael Haenlein
Associate Professor of Marketing
ESCP Europe
Paris,