[R] Expressions and Functions

[Roger D. Peng]

I can think of 2 ways:

f <- function(x) { }
body(f) <- D(expression(log(x)), "x")

Or maybe

g <- deriv(expression(log(x)), "x", function.arg = TRUE)
f <- function(x) { attr(g(x), "gradient") }

Or something along those lines.

-roger

Erin Hodgess wrote:
> Dear R People:
> 
> When the D function is used for a symbolic derivative,
> an expression is returned, which is fine.
> 
> How do you change that expression to a function, please?
> 
> I've been experimenting with substitute and deparse, but no success
> yet.
> 
> This is R 1.8.0 for Windows.
> 
> thanks in advance for the help!
> 
> Sincerely,
> Erin Hodgess
> mailto: hodgess at gator.uhd.edu
> 
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