Functions and commands 341
Create
Poly to Coef Given a polynomial, returns a vector containing the
coefficients of the polynomial. With a variable as second
argument, returns the coefficients of a polynomial with respect
to the variable. With a list of variables as the second
argument, returns the internal format of the polynomial.
symb2poly(Expr,[Var])
or
symb2poly(Expr, {Var1, Var2,…})
Example:
symb2poly(x*3+2.1) returns [3 2.1]
Coef to Poly With one vector as argument, returns a polynomial in x with
coefficients (in decreasing order) obtained from the argument
vector. With a variable as second argument, returns a similar
polynomial in that variable.
poly2symb(Vector, [Var]))
Example:
poly2symb([1,2,3],x) returns (x+2)*x+3
Roots to Coef Returns a vector containing the coefficients (in decreasing
order) of the univariate polynomial whose roots are specified
in the argument vector.
pcoef(Vect)
Example:
pcoeff([1,0,0,0,1]) returns [1,-2,1,0,0,0]
Roots to Poly Takes as argument a vector. The vector contains each root or
pole of a rational function. Each root or pole is followed by its
order, with poles having negative order. Returns the rational
function in x that has the roots and poles (with their orders)
specified in the argument vector.
fcoeff(Vector)
where Vector has the form [Root1,
Oder1, Root2, Order2, …])
Example:
fcoeff([1,2,0,1,3,-1]) returns (x-1)^2*x*(x-3)^-
1