search for: argmin

Hi all, I want to use "which.max" to identify the maximum in a 2D array/matrix and I want "argmin" and return the row and column indices. But "which.max" only works for vector... Is there any convinient way to solve this problem? Thanks a lot! [[alternative HTML version deleted]]

Hi all Just wondering whether one can undertake Lp norm estimation (a type of regression analysis) in R? i.e. argmin S ( | y(i) - x(i)b | ^p ) where: * S is the summation over observation i= 1,2,...,n * y is a vector of n observations * x is an n by p matrix of explanatory variables * b is a p by 1 vector of beta coefficients and * p is a constant to be estimated such that p>= 1 Regards Allan...

Hi, I'm having trouble using the constrOptim function to generate the 9-component vector argmin of the function ELfsds: ELfsds <- function(pvechat){ LG=0 for(i in 1:9){ LG=LG+log(pvechat[i]) } return(-LG) } with accompanying gradient function: gradfunc <- function(thetavec){ g=1/(9*thetavec) return(g) } The constraints on the optimization problem are: 1 - components of pote...

Dear all, I am facing the following problem in optimization: w = (d, o1, ..., op, m1, ..., mq) is a 1 + p + q vector I want to determine: w = argmin (a - d(w))' A (a - d(w)) where a is a 1xK marix, A is the covariance matrix of vector a, d(w) is a 1xK vector which parameters are functions of parameters d, o1 .. op, m1 .. mq. Is there some function to solve this problem easily? I know optim() and ucminf() for one-dimensional optimization (...

Dear list, hi ! I am a R beginner and I have a function to optimize . alpha = argmin{ f(x,alpha) } I want alpha to be in [0,1]. Is there any function that can work? I use nlm() but i can't fix the domain of alpha. thanks in advance _______________________ Jiang Peng, Ph.D. Candidate Department of Mathematics & Antai college of Economics and Management Shanghai...

Hi! I have a problem of finding a specific value in a column. For example, I have a matrix with say 2 columns X Y 1 -2.0341602 9.036689e-05 2 -1.4287230 1.807338e-04 3 -1.1194402 2.711007e-04 4 -1.0327582 3.614676e-04 5 -0.8130556 4.518344e-04 6 -0.7138212 5.422013e-04 7 -0.6634425 6.325682e-04 8 -0.6512083 7.229351e-04 9

Estimado Jesús Para Fernández En teoría es ese material, lo vi muy rápido y en la parte genética tiene cosas que biológicamente no son así, hay un libro de Falconer, Introducción a la genética cuantitativa, que tiene escrita la parte matemática, hay un abismo entre la biología y los ingenieros que se inspiran en la biología. Yo pensaba en la resolución de un problema real, aunque relativamente

....com> > To: R-help at stat.math.ethz.ch > Subject: [R] returning the largest element in an array/matrix? > > > Hi all, > > > > I want to use "which.max" to identify the maximum in a 2D array/matrix > > and I want "argmin" and return the row and column indices. > > > > But "which.max" only works for vector... > > > > Is there any convinient way to solve this problem? > > > > Thanks a lot! > > > > [[alternative HTML version deleted]] > > > >...

Hello, In the latest 'Scientific Computing World' magazine (issue 78, p. 22), there is a review on free statistical software by Felix Grant ("doesn't have to pay good money to obtain good statistics software"). As far as I know, this is the first time that R is even mentioned in this magazine, given that it usually discuss commercial products. In this article, the analysis

Hello, In the latest 'Scientific Computing World' magazine (issue 78, p. 22), there is a review on free statistical software by Felix Grant ("doesn't have to pay good money to obtain good statistics software"). As far as I know, this is the first time that R is even mentioned in this magazine, given that it usually discuss commercial products. In this article, the analysis