
Hello R-users
   
  I am new to R and trying to write some functions. I have problems writing functions that takes a data set as an arguement and uses variables in the data. I illustrate my problem with a small example below:
   
   sample data   #------------------
  visual24<-rnorm(30,3,5)
  visual52<-rt(30,7)
  dats<- data.frame(cbind(visual24,visual52))
  remove(visual24, visual52)
   
  # first code
  #--------------
  st <-function(data,x,y){
  rcc<-coef(lm(y~x))
  plot(x,y)
  abline(rcc[1],rcc[2])
  }
  st(data=dats,x=dats$visual24,y=dats$visual52)
   
  This code works fine, but with such a code the data as an arguement to the funtion is not necessary. 
  However, i wish to write a function that reads the variables from the data directly.
  I tried using the function below but it does not work. 
   
  # second code
  #------------------
  st <-function(data,x,y){
  rcc<-coef(lm(data$y~data$x))
  plot(data$x,data$y)
  abline(rcc[1],rcc[2])
  }
  st(dats,visual24,visual52)
   
  I wish to inquire if any one has an idea of what i need to adjust in the function so that it works.
  I believe that the referencing $x or $y in the function is not doing the correct thing.
   
  Better still, will it be a problem if i code the functions as in the first code above?
  I mean given that they will be used to create a library
   
  Best regards
  Pryseley
   


		
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