converting string fractions to numerics

Dear R People:

Suppose I have the following:

"pi/2"

and I would like it to be 1.57.....

Using as.numeric, here is my result:

as.numeric("pi/2")

[1] NA
Warning message:
NAs introduced by coercion

Is there a way to produce the numeric result, please?

Thanks,
Erin

Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: erinm.hodgess at gmail.com