[R] Beginer data.frame

[David Winsemius]

On Jan 12, 2010, at 6:17 AM, Jean-Baptiste Combes wrote:

> Hello,
>
> I use R 2.10, and I am new in R (I used to use SAS and lately  
> Stata), I am
> using XP.
>
> I have a data which has a data.frame format called x.df (read from a  
> csv
> file). I want to take from this data observations for which the  
> variable
> "Code" starts with an "R". I took all the Code and put them into a  
> vector
> vec<-grep("R[A-Z][A-Z]",x.df$Code,value=TRUE)

vec is going to be a vector of row numbers that can be used to address  
the data.frame
>
> Then I created a function that is supposed to take all the lines in  
> the my
> data x.df for which "Code" equals one value of "vec". See the code  
> below
> where I created a loop to do that.
>
That seems to be a very short R one-liner:

data[vec, ]

?"["

-- 
David.
>> myfunc<-function(data,var2,var1)
> + {
> + i=1
> + while (i<632){     #where does that come from ?
> + line<-subset(data,var2==var1[i])
> + if (i==1){
> + df<-line
> + df<-data.frame(df)
> + }
> + else {
> + line<-data.frame(line)
> + df<-rbind(df,line)
> + }
> + i<-i+1
> + }
> + fix(df)
> + }
>>
>
> The results of my program higly depend on the few last lines of the  
> program.
> If I put "fix(df)", as above, the function opens a window with my  
> data and
> it seems a sensible results (I have not checked in details but I  
> barely have
> what I am suppose to get).
>> myfunc<-function(data,var2,var1)
> ...
> + }
> + df<-data.frame(df)
> + print(is.data.frame(df))
> + }
>> myfunc(x.df,x.df$Code,vec)
> [1] TRUE
>> print(is.data.frame(df))
> [1] FALSE
>
> In the case above I ask whether or not the "df" is a data.frame and  
> the
> answer is true, when the program has ended, I ask again and the  
> answer is
> false.
>
> Could anyone tell me what to do to get this data and could anyone  
> tell me
> why those differences in the results?
>
>> as.data.frame(df)
> Erreur dans as.data.frame.default(df) :
>  impossible de convertir automatiquement la classe  "function" en un
> tableau de données (data.frame)
>>
>
> 	[[alternative HTML version deleted]]
>
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