search for: ipop

hi everyone, ipop very quickly and accurately identifies the correct parameters in a toy dataset i built, but when i use ipop on the real dataset i get values for the parameters " primal(res) " that are less than zero, even though i specify zero for the lower bound : l = rep(0, length(c)) , where length...

...Sorry Megh Dal <megh700004@yahoo.com> wrote: Date: Wed, 7 May 2008 02:45:09 -0700 (PDT) From: Megh Dal <megh700004@yahoo.com> Subject: Re: [R] Solution of function To: Berwin A Turlach <berwin@maths.uwa.edu.au> Hi Berwin, Thanks for having look on my problem. However on ipop() function I see following: ipop solves the quadratic programming problem : min(c'*x + 1/2 * x' * H * x) subject to: b <= A * x <= b + r l <= x <= u But my problem is not to find maxima or minima rather to get solution at that defined region. How to modify that fun...

Hi, I am mounting a server of email with the Dovecot as MUA, i would like to restrict the access to imap and ipop to one determined range of IP. As I configure this in dovecot.conf, I did not understand the functioning of listen = * or [: ] Thanks a lot, Clovis -- Cl?vis Trist?o -------------------:-oo)---- Seja Legal, use GNU/Linux ----------------------------------------

Dear R users, I'm trying to run the Support Vector Regression by a general quadratic programming function like ipop ( ) in kernlab or solve.QP ( ) in quadprog packages. Since they are general, their application in Support Vector Regression can lead to misunderstanding, particularly when constructing matrices. Even their examples are general and applied in Support Vector Classification. Could anybody...

...plorer - and I am a Mac user. Yes, I've contacted them, many times - many levels, and just hit a brick wall each time. The website states: The State Controller's Office currently supports Internet Explorer 6.0 and 7.0. When accessing the following SCO applications: Form-W2, I-TIME, IBIS, IPOPS, Online Pay Stubs, Online Reporting, P-Card and Travel Express, Internet Explorer 6.0 or 7.0 is required. Though other browsers exist, the SCO only supports Internet Explorer 6.0 and 7.0. Some SCO applications may be accessed with other browsers, but complete functionality is not guaranteed. It...

I forgot to attach the problem data, 'quadprog.Rdata' file, in my prior email. I want to report a following error with quadprog. The solve.QP function finds a solution to the problem below that violates the last equality constraint. I tried to solve the same problem using ipop from kernlab package and get the solution in which all equality constraints are enforced. I also tried an old version of quadprog, Version: 1.4-11, Date: 2007-07-12 and my problem is solved correctly. I have tried to contact Berwin A. Turlach <Berwin.Turlach at gmail.com> (maintainer for qua...

Hi everybody, I''m using R on a 64-bit Ubuntu 9.04 (Jaunty). I prefer to install R packages from source, even if they are available in Synaptic. The problem is that I can''t install/compile kernlab. Everything works fine until it gets to the lazy loading part: ** preparing package for lazy loading Creating a new generic function for "terms" in "kernlab"

Hi R-list, I am new to optimization in R and would appreciate help on the following question. I would like to minimize the following function using two constraints: ###### fn <- function(par,H,F){ fval <- 0.5 * t(par) %*% H %*% par + F%*% par fval } # matrix H is (n by k) # matrix F is (n by 1) # par is a (n by 1) set of weights # I need two constraints: # 1.

...ts Analysis o kcca() : Kernel Canonical Correlation Analysis o kfa() : Kernel Feature Analysis o sigest() : Hyperparameter estimation for the Gaussian and the Laplacian kernels o inchol() : Incomplete Cholesky decomposition method o csi() : Cholesky decomposition with side information o ipop() : Interior point-based Quadratic Optimizer Kernlab also includes a range of functions enabling the easy implementation of new kernel methods including functions for computing commonly used kernel expressions (e.g. kernel matrix, kernel expansion, etc.) and implementations of nine kernels (e.g. L...

...ts Analysis o kcca() : Kernel Canonical Correlation Analysis o kfa() : Kernel Feature Analysis o sigest() : Hyperparameter estimation for the Gaussian and the Laplacian kernels o inchol() : Incomplete Cholesky decomposition method o csi() : Cholesky decomposition with side information o ipop() : Interior point-based Quadratic Optimizer Kernlab also includes a range of functions enabling the easy implementation of new kernel methods including functions for computing commonly used kernel expressions (e.g. kernel matrix, kernel expansion, etc.) and implementations of nine kernels (e.g. L...

I wonder whether R has methods for constrained fitting of linear models. I am trying fm<-lm(y~x+I(x^2), data=dat) which most of the time gives indeed the coefficients of an inverted parabola. I know in advance that it has to be an inverted parabola with the maximum constrained to positive (or zero) values of x. The help pages for lm do not contain any info on constrained fitting. Does anyone

Hi, I'm quite new at R and I haven't found the answer to my question anywhere on the net, so either it is trivial or not documented. So, bare with be. I am using the quadprog package and its solve.QP routine to solve and quadratic programming problem with inconsistent constraints, which obviously doesn't work since the constraint matrix doesn't have full rank. A way to solve this

...> The help pages for lm do not contain any info on constrained fitting. > > Does anyone know how to? Look at the package nnls on CRAN. According to your subject line, you are trying to solve what is known as a quadratic program, and there are at least two quadratic programming solvers (ipop in kernlab and solve.qp in quadprog) available for R. HTH. Cheers,     Berwin =========================== Full address ============================= Berwin A Turlach                            Tel.: +65 6516 4416 (secr) Dept of Statistics and Applied Probability        +65 6516 6650 (self) Facu...