[R] Conversion from expression to numeric

[Paul Smith]

Dear All

I am trying to convert from the type "expression" to the type
"numeric". The following works:

> x <- expression(6.2)
> as.numeric(as.character(x))
[1] 6.2

However, the following does not work:

> x <- expression(62/100)
> as.numeric(as.character(x))
[1] NA
Warning message:
NAs introduced by coercion

Any idea about how to deal with the second case?

Thanks in advance,

Paul