similar to: Rpart - best split selection for class method and Gini splitting index

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Dear all, I'm trying to manage with user defined split function in rpart (file rpart\tests\usersplits.R in http://cran.r-project.org/src/contrib/rpart_3.1-34.tar.gz - see bottom of the email). Suppose to have the following data.frame (note that x's values are already sorted) > D y x 1 7 0.428 2 3 0.876 3 1 1.467 4 6 1.492 5 3 1.703 6 4 2.406 7 8 2.628 8 6 2.879 9 5 3.025 10 3 3.494

Dear R users, I'm using the rpart package to build classification trees. I'm interested in implementing the ordered Twoing as a splitting criterion. Does anyone have experience with this task ? Thank you for your help Paolo Paolo Radaelli Dipartimento di Metodi Quantitativi per le Scienze Economiche ed Aziendali Facolt? di Economia Universit? degli Studi di Milano-Bicocca Via Bicocca

Dear all, I'm writing my own method to be used in Rpart by defining the list of functions named init, split and eval. I'm following the example given in the file 'tests/usersplits.R' in the sources. By now I'm able to define the split function (and it works correctly in the tree construction) while I have some problems with the init and the eval function. The task I'm

Dear R users, I'm working with the rpart package and want to evaluate the performance of user defined split functions. I have some problems in understanding the meaning of the xval argument in the two functions rpart.control and xpred.rpart. In the former it is defined as the number of cross-validations while in the latter it is defined as the number of cross-validation groups. If I am

Dear R users, I know cross-validation does not work in rpart with user defined split functions. As Terry Therneau suggested, one can use the xpred.rpart function and then summarize the matrix of the predicted values into a single "goodness" value. I need only a confirmation: set for example xval=10, if I correctly understood a single column of the matrix obatined by xpred.rpart gives

Dear Gregory R. Warnes, I'm a phd student in statistics, at the University of Milano Bicocca. I'm interested to the methods of estimate the parameters of the Dirichlet distribution. Do you have implemented an algorithm in R? If so, can you give me the script? or, in general, some helps? Best Regards Gianna --------------------------------------------------------------- Gianna Monti

Dear List, quantile(x) function allows to obtain specified quantiles of a vector of observations x. Is there an analogous function to compute quantiles in the case one have the vector of the observations x and the correspondent vector f of relative frequencies ? Thank you Paolo Radaelli [[alternative HTML version deleted]]

Someone knows the existence of a function to sum the elements of the same place A[i,j] B[i,j] of a matrix?thank you -- Dr. Daniele Riggi, PhD student University of Milano-Bicocca Department of Statistics Building U7, Via Bicocca degli Arcimboldi, 8 20126 Milano, Italy cell. +39 328 3380690 mailto: daniele.riggi@gmail.com [[alternative HTML version deleted]]

Hi, I would like to know if it is possible to have a "R code" to estimate the parameters of a mixture of bivariate (or multivariate) normals via EM Algorithm. I tried to write it, but in the estimation of the matrix of variance and covariance, i have some problems. I generate two bidimensional vectors both from different distribution with their own vector means and variance and

Hi R-users,I'm trying to solve a non linear equation, to find the degrees of freedom of a mixture of t student. I'm sure i wrote the minimization equation in the right way, but when i try to run the EM algorithm to estimate the parameters of the mixture, the following error will appear: Error in uniroot(function(z) log(z/2) - digamma(z/2) + 1 - log((z + d)/2) + : f() values at end

Dear all, I would like to ask information about the package mvtnorm in R. It is very useful for me the "qmvnorm" comand, but I see that it can compute only quantile for equicoordinate. Is it possible to have a curve (or a set of values) if we don't want equicoordinates? Thank you Best regards Antonio. -- Antonio Lucadamo, Dipartimento di Scienze Economiche e Metodi Quantitativi

Dear all, I'm using the ellipse package and I would like to verify if the confidence region that I build with this package can be equivalent to an Union Intersection Test. I used different value for the t-statistic but I can not find the right equivalence. Does someone know how to choose the right value? Thanks a lot. Antonio -- Antonio Lucadamo, Dipartimento di Scienze Economiche e

Dear R users, I am in trouble using the function solve(matrix) in a loop. When it happens that I have a singular matrix, I get an error message saying so and the loop stops. My question is if there in any way to keep on going in the loop. Thank you in advance, Laura *---------------------------------------------------------* Laura Antolini, PhD Department of

Dear all, could you please suggest me the package I have to install in order to use ranks statistics in regression models (R-Estimators, wilcoxon scores ...) Thanks and Happy Easter Paolo Radaelli [[alternative HTML version deleted]]

Great! Please let the mailing list know if you run into any further problems. -- Peter Paolo Pedroni wrote: > > Alle 16:38, venerd=EC 25 agosto 2006, hai scritto: > > Paolo, > > > > I recently fixed some bugs regarding the report descriptor retrieval. > > Please try it with the newest development version from SVN. You can > > follow the instructions at >

Running on an Alpha machine which reports (uname -a) OSF1 bsdx01.bs.ehu.es V4.0 878 alpha and using the binary distribution put together by Albrecht Gebhardt (in http://cran.at.r-project.org/bin/osf/osf4.0/tar/alpha_ev5/) I obtain core dumps whenever I try to use package rpart. I have R REMOVE'd the rpart package, downloaded the source rpart_1.0-7.tar from CRAN and

Dear R-listers, I would like to carry out a very basic descriptive analysis of homicides rates in Italy, taking into account both the spatial dimension (103 provinces) and the temporal dimension (10 years), but no covariates. In practice, what I would like to do is to describe spatio-temporal variation of homicide rates, identifying those combinations of province-year where the homicide rate

If I use the Ineq library and the Gini function in this way: >Gini(c(100,0,0,0)) I obtain the result 0.75 instead of 1 (that is the perfect inequality). I think Gini's formula in Ineq is based on a formula as reported here: http://mathworld.wolfram.com/GiniCoefficient.html but in the case of perfect inequality: x_1=.......=x_n-1 =0 x_n>0 these formula are equal to 1 - 1/n, not to

Hello dear R-help members, I would appreciate any help in understanding how the rpart function computes the "improve" (which is given in fit$split) when using the split='information' parameter. Thanks to Professor Atkinson help, I was able to find how this is done in the case that split='gini'. By following the explanation here: