access a column of a dataframe without qualifying the name of the column
On Dec 29, 2010, at 7:11 PM, John Sorkin wrote:
I am trying to write a function that will access a column of a data frame without having to qualify the name of the data frame column as long as the name of the dataframe is passed to the function. As can be seen from the code below, my function is not working:
Not sure what the verb "qualify" means in programming. Quoting?
df <- data.frame(x=1:10,y=11:20)
df
test <- function(column,data) {
print(data$column)
}
test(x,df)
I am trying to model my function after the way that lm works where
one needs not qualify column names, i.e.
> df <- data.frame(x=1:10,y=11:20)
> test <- function(column,dat) { print(colname <-
deparse(substitute(column)))
+ dat[[colname]]
+ }
>
> test(x,df)
[1] "x"
[1] 1 2 3 4 5 6 7 8 9 10
>
David.
>
>
> fit1<- lm(y~x,data=df)
>
>
> John David Sorkin M.D., Ph.D.
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology
> Baltimore VA Medical Center
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David Winsemius, MD
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