D(expr, namevec) deriv(expr, namevec, function.arg = NULL, tag = ".expr")
expr
| expression which should be derivated |
namevec
| character vector, giving the variable names with respect to which derivatives will be computed. |
function.arg
| ... ?? ... |
tag
| ... ?? ... |
D is modelled after its S pendant for taking simple symbolic
derivatives.
deriv is a generic function with a default and a
formula method. It returns a call for computing
the expr and its (partial) derivatives, simultaneously.
It uses so called "algorithmic derivatives".
Currently, deriv.formula just calls deriv.default after
extracting the expression to the right of ~.
D returns an expression and therefore can easily be iterated for
higher derivatives.
deriv returns a call object which becomes an
expression when evaluated once.
Evaluation of the latter expression returns the function values with a
".gradient" attribute containing the gradient matrix.
RHOME/src/main/deriv.c.
It's author, MM, has only got a vague idea and thinks that a help page
is better than none....
nlm for numeric minimization which should make use of derivatives.