This question is about column names returned by the aggregate function.
Consider the following example
df <- data.frame(
id = c(rep('11',30),rep('22',30),rep('33',30)),
value = c(rnorm(30,2,0.5), rnorm(30,3,0.5), rnorm(30,6,0.5))
)
aggregate(df[,c("value"),drop=FALSE], by=list(id=df$id), max)
output:
id value
1 11 2.693528
2 22 3.868400
3 33 6.942519
aggregate(df$value, by=list(id=df$id), max)
output:
id x
1 11 2.693528
2 22 3.868400
3 33 6.942519
(YMMV on output values since data is randomly generated)
I would like to be able to name the output column as max.value. I realize I
can add the following statement:
colnames(df)[match("value",colnames(df))] <- "max.value"
Is there a way of having aggregate return computed column names which can be
specified when calling the function (i.e. aggregate)?
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