similar to: optimization problem

Displaying 20 results from an estimated 1000 matches similar to: "optimization problem"

2009 Nov 12
2
A combinatorial optimization problem: finding the best permutation of a complex vector
Hi, I have a complex-valued vector X in C^n. Given another complex-valued vector Y in C^n, I want to find a permutation of Y, say, Y*, that minimizes ||X - Y*||, the distance between X and Y*. Note that this problem can be trivially solved for "Real" vectors, since real numbers possess the ordering property. Complex numbers, however, do not possess this property. Hence the
2009 Nov 12
2
Non linear programming optimization (which package to use?)
Hello, 1) Is there any nonlinear programming optmizer that I can user for the following problem? Obj function: (max) revenue = price * volume Constraints: price and volume pair must be from the following variable data set: Variable data set: # price volume 1 10 500 2 20 450 3 30 330 4 40 250 5 50 190 Expected result: 10,000 (variable row#4) 2) Could it also be possible for the suggested
2010 Mar 21
2
Find a rectangle of maximal area
For an application in image processing -- using R for statistical purposes -- I need to solve the following task: Given n (e.g. n = 100 or 200) points in the unit square, more or less randomly distributed. Find a rectangle of maximal area within the square that does not contain any of these points in its interior. If a, b are height and width of the rectangel, other constraints may have to be
2009 Dec 18
2
NLS-Weibull-ERROR
Hello I was trying to estimate the weibull model using nls after putting OLS values as the initial inputs to NLS. I tried multiple times but still i m getting the same error of Error in nlsModel(formula, mf, start, wts) : singular gradient matrix at initial parameter estimates. The Program is as below > vel <- c(1,2,3,4,5,6,7,8,9,10,11,12,13,14) > df <- data.frame(conc, vel) >
2010 Aug 27
3
R-help
Respected R Help Team Members, I am venkatesh .B , doing mtech in *University of Hyd,HYDERABAD. *i want know , is there any package that contains Hungarian algorithm, that solves linear assignment problem. thanking you. * * -- *Sincerely B.venkatesh University of Hyd,HYDERABAD 9440186746* [[alternative HTML version deleted]]
2012 Feb 19
2
installing the package Rcplex
Dear All,   I have difficulty in installing the package of Rcplex. Its description web is at http://cran.r-project.org/web/packages/Rcplex/index.html   First, I tried -------------------------------------------------------------------------------------------------- url <- "http://cran.r-project.org/src/contrib/Rcplex_0.3-0.tar.gz"; download.file(url, basename(url),
2012 Jul 27
1
an optimization problem and installation of the package Rcplex
Hello, I am an R user who wants to solve an optimization problem. To do so, I tried to install the package Rcplex on my computer (Windows7-64), so I did the same as installation Instructions<http://www.geeklog.net/docs/english/install.html> and edited the file "Makevars.win" by adding the path "C:/Program Files/IBM/ILOG/CPLEX_Studio_Preview124/cplex/include" (where the
2011 May 17
1
simprof test using jaccard distance
Dear All, I would like to use the simprof function (clustsig package) but the available distances do not include Jaccard distance, which is the most appropriate for pres/abs community data. Here is the core of the function: > simprof function (data, num.expected = 1000, num.simulated = 999, method.cluster = "average", method.distance = "euclidean", method.transform =
2013 Sep 26
1
Installing Rcplex
Hi, I have tried to install the R package Rcplex on windows xp without success. I have only cplex_studio124.win-x86-32 version. I have modified the makevars.win file as indicated in the installation guide ( http://cran.r-project.org/web/packages/Rcplex/INSTALL ), then I zipped the whole folder to order an installation from a zipped file (utils :menuInstallLocal()) The message I had is file
2010 Jun 15
2
Integration problem: error in invoking an outside function
Dear all, Currently I am trying to integrate a function which depends on four variables, two of which are given, one is given in the integrate function, so there is one variable to integrate on. The code is as follows: Pmatrix = function(th) { P = matrix(nrow=6, ncol=6, data=0) P[1,1] = P[2,1]=P[3,2]=P[4,3]=P[5,4]=P[6,5]= exp(-th) P[,6] = 1-exp(-th) return(P)} lim.verd =
2008 Feb 11
2
Viable Approach to Parallel R?
All, We are researching approaches to parallel R with the end goal of running R in a distributed manner on a Linux cluster. We expect of course to do some work decomposing our problems to be task-parallel or data-parallel, but wouldn't mind getting an initial boost working with "embarrassingly parallel" code sections and one of the approaches below. Incidentally our environment
2008 Feb 15
2
help on using try() to catch an error
Dear R Users, I have the following glm, which I am running several times in a loop (I am not including the full code): reduced_model <- NULL; full_model <- NULL; reduced_model <- try(glm.fit(X4,n,family=poisson(link="log"))) full_model <- try(glm.fit(X5,n,family=poisson(link="log"))); On some occasions, an error is produced, which is why I have attempted to work
2005 May 03
1
maximization help :
Given a vector : pvec=(p1,p2,.... p J) with sum(pvec)=1, all the elements are non-negative, that is, they are probabilities a matrix A ( N* J ), with the elements alpha(ij) are 0 or 1 I want to MAXIMIZE THE RESULT RESULT= product( i=1, to N [ sum ( alpha(ij)* pj , j =1,to J ) ] ) thus, I need to get pvec. how should I do ? for example
2011 Mar 19
2
problem running a function
Dear people, I'm trying to do some analysis of a data using the models by Royle & Donazio in their fantastic book, particular the following function: http://www.mbr-pwrc.usgs.gov/pubanalysis/roylebook/panel4pt1.fn that applied to my data and in the console is as follows: > `desman.y` <- structure(c(3L,4L,3L,2L,1L), .Names = c("1", "2", "3",
2016 Mar 14
2
[PATCH v1 01/19] mm: use put_page to free page instead of putback_lru_page
On 03/11/2016 08:30 AM, Minchan Kim wrote: > Procedure of page migration is as follows: > > First of all, it should isolate a page from LRU and try to > migrate the page. If it is successful, it releases the page > for freeing. Otherwise, it should put the page back to LRU > list. > > For LRU pages, we have used putback_lru_page for both freeing > and putback to LRU
2016 Mar 14
2
[PATCH v1 01/19] mm: use put_page to free page instead of putback_lru_page
On 03/11/2016 08:30 AM, Minchan Kim wrote: > Procedure of page migration is as follows: > > First of all, it should isolate a page from LRU and try to > migrate the page. If it is successful, it releases the page > for freeing. Otherwise, it should put the page back to LRU > list. > > For LRU pages, we have used putback_lru_page for both freeing > and putback to LRU
2009 Jun 07
1
Inf in nnet final value for validation data
Hi, I use nnet for my classification problem and have a problem concerning the calculation of the final value for my validation data.(nnet only calculates the final value for the training data). I made my own final value formula (for the training data I get the same value as nnet): # prob-matrix pmatrix <- cat*fittedValues tmp <- rowSums(pmatrix) # -log likelihood
2011 Jun 16
2
Bayesian Credible Intervals for a Proportion
I am trying to calculate Bayesian Credible Intervals for a proportion (disease prevalence values to be more specific) and am having trouble using R to do this. I am working with ncredint() function but have not had success with it. Please help! Example: Positive samples = 3 Total sampled = 10 Prevalence = 0.3 pvec <- seq(1,10,by=1) npost = dbinom(pvec,10,prob=0.3, log=FALSE) ncredint(pvec,
2008 Jan 25
1
increasing speed for permutations of glm
Dear R Programmers, I am trying to run a Poisson regression on all pairs of variables in a data set and obtain the permutation distribution. The number of pairs is around 100000. It seems my code will take weeks to run, unless I try something else. Could you give me any suggestions on how to improve the speed of the code below, or any general suggestions on how I may accomplish this task. Thanks
2003 Nov 25
2
Lambert's W function
Hello List does anyone have an R function for the Lambert W function? I need complex arguments. [the Lamert W function W(z) satisfies W(z)*exp(W(z)) = z but I could'nt even figure out how to use uniroot() for complex z] -- Robin Hankin Uncertainty Analyst Southampton Oceanography Centre SO14 3ZH tel +44(0)23-8059-7743 initialDOTsurname at soc.soton.ac.uk (edit in obvious way; spam