polylib::Dpoly
-- differential
operator for polynomialsIf f
is a polynomial in the indeterminates
x1
through xn,
polylib::Dpoly
([i1,..,ik], f)
computes the
k-th partial derivative (&partial;k
f)/(&partial;xi1 ...&partial;xik )
.
polylib::Dpoly
(f)
returns the derivative
of f
with respect to its only variable for an univariate
polynomial f
.
polylib::Dpoly(f)
polylib::Dpoly(indexlist, f)
f |
- | polynomial |
indexlist |
- | list of positive integers |
polylib::Dpoly
returns a polynomial in the same
indeterminates and over the same coefficient ring as the input.
f
indexlist
is greater than the
number of indeterminates of f
, the zero polynomial is
returned.polylib::Dpoly(
[ ], p)
returns
p
.d
, then this domain must have the method "intmult":
d::intmult(e,i)
, that must calculate the integer multiple of a
domain element e
and a positive integer
i
.polylib::Dpoly
is a function of the system
kernel.We differentiate a univariate polynomial with respect to its only indeterminate. In this case, we may leave out the first argument.
>> polylib::Dpoly(poly(2*x^2 + x + 1));
poly(4 x + 1, [x])
No we differentiate a bivariate polynomial, and must specify the indeterminate in this case.
>> polylib::Dpoly([1], poly(x^2*y + 3*x + y, [x, y]));
poly(2 x y + 3, [x, y])
It is also possible to compute second or higher partial derivatives.
>> polylib::Dpoly([1, 2], poly(x^2*y + 3*x + y, [x, y]));
poly(2 x, [x, y])
Dpoly