Compute partial derivatives of a multivariate polynomial.

This is a deriv method for mpoly objects. It does not call the stats::deriv().

# S3 method for mpoly
deriv(expr, var, ...)

Arguments

expr	an object of class mpoly
var	character - the partial derivative desired
...	any additional arguments

Value

An object of class mpoly or mpolyList.

Examples

m <- mp("x y + y z + z^2")
deriv(m, "x")
#> y
deriv(m, "y")
#> x  +  z
deriv(m, "z")
#> y  +  2 z
deriv(m, c("x","y","z"))
#> y
#> x  +  z
#> y  +  2 z
deriv(m, "a")
#> 0
is.mpoly(deriv(m, "x"))
#> [1] TRUE
is.mpolyList( deriv(m, c("x","y","z")) )
#> [1] TRUE