[R] A function as argument of another function

[Pfaff, Bernhard]

Dear all,
I would like to write a function like:
myfun<-function(x,fn) {xx<-exp(x); x*fn(xx)}
where fn is a symbolic description of any function with its argument to be
specified. Therefore
myfun(5,"2+0.3*y^2")
should return 5*(2+0.3*exp(5)^2),
myfun(5,"log(y)") should return 5*log(exp(5)) and so on.

I tried with "expression" and others, but without success. How can I solve
my problem?

Many thanks,
vito

hello Vito,

how about:


myfun <- function(x,fn)
  {
    xx <- exp(x)
    aux <- function(y)
      {
        eval(parse(text=fn))
      }
    x*aux(xx)
  }

myfun(5,"2+0.3*y^2")

as an alternative to Ott's answer.

HTH,
Bernhard

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