I want to calculate the irr for differents columns of a dataframe called tir. So if I do irr(tir$20180201)
I get the value.
But i want replace 20180201 with the return of: last(fecha$fecha)
, that will give me 20180201 or another value.
I do: z <- paste("tir$", last(fecha$fecha), sep="")
and I try to do irr(formula(z))
and I get:
Error in parse(text = x, keep.source = FALSE) :
<text>:1:5: unexpected numeric constant
1: tir$20181201
How can I solve my problem? Thanks!