similar to: Queries about step() and stepAIC()

I am still struggling to map a character string to an object name and vice versa in R. I thought the as.name() function might work, but observe the following behaviour ... > attach(warpbreaks) > levels(tension) [1] "L" "M" "H" > levels(as.name("tension")) NULL > objectname<-as.name("tension") > objectname tension >

Dear list, I am running R2.11.1 on 32 bit windows. I am receiving messages as follows ... > require(car) Loading required package: car Error: package 'car' was built before R 2.10.0: please re-install it The package kohonen was another example. This failure appears to be fatal and not only affects the package concerned, but also all its dependents. Is there anything I can do at my

Dear List, Hopefully someone will point me to a piece of documentation that I have overlooked. I am running Rscript successfully to read and execute an R program, but have failed to find the correct syntax to route the output to a file using the Rscript command that invokes the job. I tried Rscript -e 'sink("outputfile")' script.R , but it then ignored the scriptfile. I know

Dear List, No doubt I am going around this the wrong way, and hopefully one of you will be able to tell me how to go about it the right way. I want to change the names of an object inside a function and have it stay changed in the global environment. I can only effect the change inside the function as follows ... >

This is hopefully a trivial problem for list subscribers, but I am very new to writing R functions. I wish to call an R function written by myself from another program to fit a model. I need to tell it which of the independent variables are factors. I need to do this in a generic way, so that when the list is passed, R will work through the variables in the data frame and coerce them into being

Dear List, I am writing a function in R with the facility to store models for later use in scoring. It would be very useful if I could include in the name of the file stored the name of the model object being stored, this name being chosen by the user in the function call. A simple function to store the name of an object as a character string would fit the bill, but I have not found one. name()

Dear List, I'm trying to find a way to extract the individual conditional inference trees from cforest ( a modelling function in the party package) in a manner analogous to getTree in randomForest and I'm struggling. I can see that the information is held within the ensemble list, but haven't been able to work out how this sequence of nested lists is structured or if any of the items

I have a problem getting Windows 98 clients printing to CUPS printers where I have the printer access allowed/denied by username. It appears that samba is passing the username in uppercase to CUPS as the owner of the printjob and then CUPS does not recognise that username and rejects the job. It all works under Windows NT/XP. I am running samba 3.0.20 and cups 1.1.23. The smb.conf file is below

I thought it might be of interest to the group to pass on information about a replacement SMS command we have developed for sending text messages from Asterisk. The FASTSMS command will route text messages to mobile phones in 154 countries. Applications include voicemail notifications, missed call alerts, automated text receipts for callers (e.g. call reference number), system alerts, etc, etc.

Hi, I'm in need of some help with moving a Samba PDC with LDAP backend from Fedora linux to RHEL. The DNS is also running on that server and needs to be moved also. The DNS and LDAP migration was simple enough. The new server works just fine when using it's own DNS and LDAP for authentication, and all the users appear to be intact after the LDAP import. nss_ldap is working just fine.

The birth weight example from ?stepAIC in package MASS runs well as indeed it should. However when I change stepAIC() calls to step() calls I get warning messages that I don't understand, although the output is similar. Warning messages: 1: In model.response(m, "numeric") : using type="numeric" with a factor response will be ignored (and three more the same.) Checked

Hello, I have a question pertaining to the stepwise regression which I am trying to perform. I have a data set in which I have 14 predictor variables accompanying my response variable. I am not sure what the difference is between the function "mle.stepwise" found in the wle package and the functions "step" or "stepAIC"? When would one use

Hi all,   I’m using "step" and "stepAIC" for stepwise regression. After each step, I would like to make an additional calculation based on the independent variables that have been selected until this step and their corresponding weights. Where do I have to add this calculation?   And a second question: Is it possible, to define a certain limit of factors for the regression,

Hello, I am now running a multiple linear regression program, but I do not know the difference between the command step and stepAIC. Thanks. Maggie [[alternative HTML version deleted]]

Hello dear R mailing list members. I have recently became curious of the possibility applying model selection algorithms (even as simple as AIC) to regressions of large datasets. I searched as best as I could, but couldn't find any reference or wrapper for using step or stepAIC to packages such as biglm. Any ideas or directions of how to implement such a concept ? Best, Tal --

Hi all, I've experienced this problem using step() and stepAIC() when a name of a regressors has blanks in between (R:R1.7.0, os: w2ksp4). Please look at the following code: "x" <- c(14.122739306734, 14.4831100207131, 14.5556459667089, 14.5777151911177, 14.5285815352327, 14.0217803203846, 14.0732571632964, 14.7801310180502, 14.7839362960477, 14.7862217992577)

Dear all, I cannot seem to get the R functions step or stepAIC to perform forward or stepwise regression as I expect. I have enclosed the example data in a dataframe at the end of this mail. Note rubbish is and rnorm(17) variable which I have deliberately added to the data to test the stepwise procedure. I have used wateruse.lm<-lm(waterusage~.,data=wateruse) # Fit full model

Do any R functions incorporate a sample sample size correction (e.g., Burnham and Anderson 1998). Thanks, Hank Stevens Martin Henry H. Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243 http://www.cas.muohio.edu/botany/bot/henry.html http://www.muohio.edu/ecology

Hello, I have some trouble using step() and stepAIC() functions. I'm predicting recruitment against several factors for different plant species using a negative binomial glm. Sometimes, summary(step(model)) or summary(stepAIC(model) does not select the best model (lowest AIC) but just stops before. For some species, step() works and stepAIC don't and in others, it's the opposite.

I can only assume I'm betraying my ignorance here, but this is not what I would expect. I'm getting the following from a stepwise selection (with both step and stepAIC): > step(lm(sqrt(Grids)~ SE + Edge + NH), scope=~ (Edge + SE + NH)^2) Start: AIC= 593.56 sqrt(Grids) ~ SE + Edge + NH Df Sum of Sq RSS AIC <none> 2147.0 593.6 + Edge:NH 1