It worked! thank you

        -----Original Message----- 
        From: Torsten Hothorn [mailto:[EMAIL PROTECTED] 
        Sent: Tue 22/07/2003 15:16 
        To: Luis Miguel Almeida da Silva 
        Cc: [EMAIL PROTECTED] 
        Subject: RE: [R] variable names
        
        

        On Tue, 22 Jul 2003, Luis Miguel Almeida da Silva wrote:
        
        > I didn't noticed that fact. I've already found a way to do that
        > 
        > x <- 1:40
        > colnames(df.treino) <- paste("Ncp",x,sep=".")
        > 
        > and this generates names that I can relate with the variables. Thanks anyway
        > 
        > The problem is that I use rpart in a loop and the class labels are in the 
last column. For the above example I would "type"
        > 
        > rpart(Ncp.40~.,data=df.treino)
        > 
        > But in the next step of the loop I can have only 35 variables and the class 
labels would be at the Ncp.36. So I have to refresh the formula in rpart... and that 
is my problem
        >
        
        R> df.treino <- data.frame(matrix(rnorm(25), ncol=5))
        R> thisformula <- as.formula(paste(colnames(df.treino)[ncol(df.treino)],
        "~ ."))
        R> thisformula
        X5 ~ .
        R> rpart(thisformula, data = df.treino)
        n= 5
        
        node), split, n, deviance, yval
              * denotes terminal node
        
        1) root 5 3.032904 -0.3392065 *
        
        Torsten
        
        
        >       -----Original Message-----
        >       From: Torsten Hothorn [mailto:[EMAIL PROTECTED]
        >       Sent: Tue 22/07/2003 14:57
        >       To: Luis Miguel Almeida da Silva
        >       Cc: [EMAIL PROTECTED]
        >       Subject: Re: [R] variable names
        >      
        >      
        >
        >
        >       On Tue, 22 Jul 2003, Luis Miguel Almeida da Silva wrote:
        >      
        >       > Dear helpers
        >       >
        >       > I want to use rpart several times in a loop to build a 
classification tree. My problem is that rpart needs a formula as argument and for that 
the variables need to have names and this doesn't happen in my case. Every iteration 
in the loop has a different dataset with several variables (ex. 38 or more) and so I 
can't type the names by hand every time. Is there any function that generates names 
for variables in a dataframe. If so, how can I use then the argument
        >       >
        >      
        >       If your data is organised in a data.frame, (dummy) variable names are
        >       available by default:
        >      
        >       R> mydata <- data.frame(matrix(rnorm(25), ncol=5))
        >       R> mydata
        >                 X1          X2         X3         X4          X5
        >       1  1.3806313 -0.41827136  0.9591628 -1.3351038  0.02746110
        >       2  0.5114590 -1.34111439 -0.9617552 -0.8367088 -0.06913021
        >       3 -1.7508089 -0.49387076 -1.7597395  2.3899490 -0.15209650
        >       4 -1.6753809 -1.28381808 -1.0424903  0.1002998  0.27784949
        >       5 -0.2605535 -0.09035652 -2.5786418  1.0483400 -0.70445615
        >       R> rpart(X1 ~ ., data = mydata)
        >       n= 5
        >      
        >       node), split, n, deviance, yval
        >             * denotes terminal node
        >      
        >       1) root 5 7.463698 -0.3589306 *
        >      
        >       best,
        >      
        >       Torsten
        >      
        >       > rpart(classlabels~. ,.....)
        >       >
        >       > thanks
        >       >
        >       > ______________________________________________
        >       > [EMAIL PROTECTED] mailing list
        >       > https://www.stat.math.ethz.ch/mailman/listinfo/r-help
        >       >
        >       >
        >      
        >      
        >
        >

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