Gary Collins
2006-Dec-03 22:28 UTC
[R] passing an argument to a function which is also to be a dataframe column name
any suggestions on the following gratefully welcome,
I have a dataframe, which I am subsetting via labels
atpi[, creativity]
where (for example)
atpi = as.data.frame(matrix(1:50, ncol = 5, nrow = 10))
names(atpi) = c("Q1", "Q2", "Q3", "Q4",
"Q5")
and
creativity = c("Q1", "Q3", "Q4")
I want to add an extra column to the dataframe atpi labelled
"creativity",
which is the rowsum of these 3 columns. My problem is not the rowsum but
but the passing of an argument to a function, which is being used for subsetting
but also for labelling the rowsum column. I can do a one-off hack for
creativity,
but I want to generalise this, as I have numerous subsets
like creativity) to calculate and some pre-processiing (imputing
missing data etc)...
so I'm looking for something simple along the lines of
scoring = function(x, A){
x[, A] = rowSums(x[, A])
x
}
where a call such as
scoring(atpi, creativity)
would produce something along the lines of
> atpi
Q1 Q2 Q3 Q4 Q5 creativity
1 1 11 21 31 41 53
2 2 12 22 32 42 56
3 3 13 23 33 43 59
4 4 14 24 34 44 62
5 5 15 25 35 45 65
6 6 16 26 36 46 68
7 7 17 27 37 47 71
8 8 18 28 38 48 74
9 9 19 29 39 49 77
10 10 20 30 40 50 80
Thanks in advance
Gary
Prof Brian Ripley
2006-Dec-03 22:46 UTC
[R] passing an argument to a function which is also to be a dataframe column name
I think you want
scoring <- function(x, A){
nm <- deparse(substitute(A))
x[, nm] <- rowSums(x[, A])
x
}
On Sun, 3 Dec 2006, Gary Collins wrote:
> any suggestions on the following gratefully welcome,
>
> I have a dataframe, which I am subsetting via labels
>
> atpi[, creativity]
>
> where (for example)
>
> atpi = as.data.frame(matrix(1:50, ncol = 5, nrow = 10))
> names(atpi) = c("Q1", "Q2", "Q3",
"Q4", "Q5")
>
> and
>
> creativity = c("Q1", "Q3", "Q4")
>
> I want to add an extra column to the dataframe atpi labelled
"creativity",
> which is the rowsum of these 3 columns. My problem is not the rowsum but
> but the passing of an argument to a function, which is being used for
subsetting
> but also for labelling the rowsum column. I can do a one-off hack for
> creativity,
> but I want to generalise this, as I have numerous subsets
> like creativity) to calculate and some pre-processiing (imputing
> missing data etc)...
> so I'm looking for something simple along the lines of
>
> scoring = function(x, A){
> x[, A] = rowSums(x[, A])
> x
> }
>
> where a call such as
>
> scoring(atpi, creativity)
>
> would produce something along the lines of
>
>> atpi
> Q1 Q2 Q3 Q4 Q5 creativity
> 1 1 11 21 31 41 53
> 2 2 12 22 32 42 56
> 3 3 13 23 33 43 59
> 4 4 14 24 34 44 62
> 5 5 15 25 35 45 65
> 6 6 16 26 36 46 68
> 7 7 17 27 37 47 71
> 8 8 18 28 38 48 74
> 9 9 19 29 39 49 77
> 10 10 20 30 40 50 80
>
> Thanks in advance
>
> Gary
>
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>
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595