similar to: Trees

Displaying 20 results from an estimated 7000 matches similar to: "Trees"

2006 Feb 14
2
AID / Tree Analysis in R
Dear Colleagues, I've been looking for a function that can perform a tree analysis, similar to CHAID or QUEST. The key point is that in this case the variables are not binary but nominal (10 different values), so "tree" (from the tree package) won't work. Does anybody know help? Sincerely, ___________________ Markus Preisetanz Consultant Client Vela GmbH
2009 Aug 28
3
CHAID in R
Hi..I am trying to run CHAID in R..I have installed the sofyware Party and trying to use the function ctree() to carry out the analysis. but I am getting the following message Error in terms.default(formula, data = data) : no terms component . I am having some Likert scale variable where I have variables like "Overall satisfaction"(Dependent Variable),"Product quality", Brand
2008 Jul 21
2
CART and CHAID
Can I say that RPART is a modified algo of CART and PARTY a modified of CHAID? Thanks. ---- Chua Siang Li Consultant - Operations Research Acceval Pte Ltd Tel: 6297 8740 Email: siang.li.chua at acceval-intl.com Website: www.acceval-intl.com This message and any attachments (the "message"...{{dropped:12}}
2005 Nov 24
4
Survreg Weibull lambda and p
Hi All, I have conducted the following survival analysis which appears to be OK (thanks BRipley for solving my earlier problem). > surv.mod1 <- survreg( Surv(timep1, relall6)~randgrpc, data=Dataset, dist="weibull", scale = 1) > summary(surv.mod1) Call: survreg(formula = Surv(timep1, relall6) ~ randgrpc, data = Dataset, dist = "weibull", scale = 1)
2013 Oct 16
1
Extract a predictors form constparty object (CHAID output) in R
I have a large dataset (questionnaire results) of mostly categorical variables. I have tested for dependency between the variables using chi-square test. There are an incomprehensible number of dependencies. I used the chaid() function in the CHAID package to detect interactions and separate out (what I hope to be) the underlying structure of these dependencies for each variable. What typically
2006 Jan 02
1
ARIMA?
Hi All., Following on from all the help I received earlier .. Just so as you know a well known text book (T&F) uses "repeated observations" - I think perhaps they meant repeated measures in retrospect I am a total beginer to ARIMA, but have read a a basic text. I read that ARIMA requires a minimum of 50 repeated measures in time (repeated measures)- Unfortunately, I have 8
2005 Jun 26
4
Mixed model
Hi All, I am currently conducting a mixed model. I have 7 repeated measures on a simulated clinical trial. If I understand the model correctly, the outcome is the measure (as a factor) the predictors are clinical group and trial (1-7). The fixed factors are the measure and group. The random factors are the intercept and id and group. I tried using 2 functions to calculate mixed effects.
2003 Jul 03
1
AID and CHAID: news about?
Dear R-helpers, I just search if is there something for AID and CHAID in R: one message in this list (last year) without success and no possibility. News about? If "no" let's me know because some friends are looking for thesis and this could be a usefull job. bye -- Daniele Medri
2020 Jan 02
1
New R function is.nana = is.na & !is.nan
"nana" is meant to express "NA, really NA". Your suggestion sounds good. On Thu 2 Jan, 2020, 3:38 AM Pages, Herve, <hpages at fredhutch.org> wrote: > Happy New Year everybody! > > The name (is.nana) doesn't make much sense to me. Can you explain it? > > One alternative would be to add an extra argument (e.g. 'strict') to > is.na(). FALSE by
2020 Jan 01
2
New R function is.nana = is.na & !is.nan
Hello R-devel, Best wishes in the new year. I am writing to kindly request new R function so NA_real_ can be more easily detected. Currently if one wants to test for NA_real_ (but not NaN) then extra work has to be done: `is.na(x) & !is.nan(x)` Required functionality is already at C level so to address my request there is not that much to do. Kevin Ushey made a nice summary of current R C api
2008 Aug 27
2
Seeking Code for Chaid or Similar
Quick disclaimer: I'm new to the list and I'm not sure if I'm sending this to the correct forum. If there is a better place for questions like these, please let me know! Dear R List, I'm interested in modifying a regression tree algorithm to use the difference between a control and a dosed sample as its dependent variable. I was wondering if anyone knew where I could find
2007 Feb 02
2
Regression trees with an ordinal response variable
Hi, I am working on a regression tree in Rpart that uses a continuous response variable that is ordered. I read a previous response by Pfr. Ripley to a inquiry regarding the ability of rpart to handle ordinal responses in 2003. At that time rpart was unable to implement an algorithm to handle ordinal responses. Has there been any effort to rectify this in recent years? Thanks! Stacey On
2006 Jan 16
1
gplots
Hi I am sure that this question has been asked before ... appologies in advance This - which comes out very nicely - better than the commercial stuff. plotmeans (cdpy~Dodefordpy, Data = Dataset, connect = False, minbar = 1, mean.labels = FALSE, col = "blue", barwidth = 1.5, barcol = "red", ci.label = FALSE, xlab="Onset", pch = 15, par(las =2)). Only one snag I
2008 Dec 29
2
dudas
Quer?a saber si existe alguna funci?n de R para realizar el algoritmo CHAID de ?rbol de clasificaci?n, existen de J48 por ejemplo pero no encuentro nada de este algor?tmo. Muchas gracias y un cordial saludo, Juan -- ========================================================= Juan Antonio Gil Pascual Prof. Titular de M?todos de Investigaci?n en Educaci?n correo: jgil at edu.uned.es web:
2012 Dec 27
0
Node Information - Decision Trees
Hi All, I need to access the node informations (viz. child nodes, split variable, split criterion etc.) for different trees packages like, CHAID, rpart, party etc. Is there an in-built function which I can use to get the requied info? Thanks a lot in advance!! Regards Ashish Kumar [[alternative HTML version deleted]]
2009 Nov 10
3
NetCDF output in R
Dear CSAG R users, I will be glad if someone can point out what I am doing wrong or not doing at all in this. I am trying to write out netcdf file in R. I have 26 time step but only the first time step is written. For example: >library(ncdf) >path <- '/home/work/' >forecast <- open.ncdf(paste(path,'cam.1980.2005.nc',sep="")) > fore <-
2009 Nov 10
3
NetCDF output in R
Dear CSAG R users, I will be glad if someone can point out what I am doing wrong or not doing at all in this. I am trying to write out netcdf file in R. I have 26 time step but only the first time step is written. For example: >library(ncdf) >path <- '/home/work/' >forecast <- open.ncdf(paste(path,'cam.1980.2005.nc',sep="")) > fore <-
2012 Dec 21
1
How to run chaid in R
Could you please let me know how to run chaid in R.     Thanks, Saumyha [[alternative HTML version deleted]]
2007 Jan 29
3
comparing random forests and classification trees
Hi, I have done an analysis using 'rpart' to construct a Classification Tree. I am wanting to retain the output in tree form so that it is easily interpretable. However, I am wanting to compare the 'accuracy' of the tree to a Random Forest to estimate how much predictive ability is lost by using one simple tree. My understanding is that the error automatically displayed by the two
2011 Apr 08
4
Rpart decision tree
Dear useRs: I try to plot an rpart object but cannot get a nice tree structure plot. I am using plot.rpart and text.rpart (please see below) but the branches that connect the nodes overlap the text in the ellipses and rectangles. Is there a way to get a clean nice tree plot (as in the Rpart Mayo report)? I work under Windows and use R2.11.1 with rpart version 3.1-46. Thank you. Tudor ...