# deriv: Partial differentitation

## Description

Partial differentiation with respect to any variable

## Usage

# S3 method for multipol
deriv(expr, i, derivative = 1, ...)

## Arguments

i

Dimension to differentiate with respect to

derivative

How many times to differentiate

...

Further arguments, currently ignored

## Examples

# NOT RUN {
a <- as.multipol(matrix(1:12,3,4))
deriv(a,1) # standard usage: derivfferentiate WRT x1
deriv(a,2) # differentiate WRT x2
deriv(a,1,2) # second derivative
deriv(a,1,3) # third derivative (zero multipol)
# }