[R] Derivative of a function

From: Gabriel Rodrigues Alves Margarido <gramarga_at_carpa.ciagri.usp.br>
Date: Tue 05 Jul 2005 - 12:47:56 EST

Suppose I have a simple function that returns a matrix, such as:

test <- function(x){ return(matrix(c(x,x^2,x^3,x^4),2,2)) }

so that test returns:
[ x x^3 ]
[ x^2 x^4 ]

Is it possible for me to get the derivative of an expression such as:

c(1,0) %*% test() %*% c(0,1)

The vectors are used just to "index" the matrix. I don't want a value, but the expression to work with (in that case, the expected expression would be 3*x^2)...

Tried functions D and deriv in many ways, but no success. I will be grateful if anyone can help.

R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Tue Jul 05 12:56:55 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:33:12 EST