Graphics Reference
In-Depth Information
Chapter 6
Polynomials and Graphics
Interpolation
6.1 Polynomial Expressions
The content of this chapter refers to work with polynomials and polynomial interpolation. We will study the
commands that enable MATLAB to perform all operations with polynomials, working with their roots and polynomial
interpolation.
MATLAB enables several commands for handling algebraic polynomial expressions. Let's take a look at some of
these commands:
conv(a, b)
gives the vector with the coefficients of the product of polynomials whose
coefficients are elements of the vectors
a
and
b.
[q, r] = deconv(a, b)
gives the vector
q
with the coefficients of the quotient of polynomials
whose coefficients are elements of the vectors
a
and
b
, and the vector
r
, which is the
polynomial remainder from division.
poly2sym(a)
is a Symbolic toolbox function that generates an object of the sym class
creating the polynomial whose coefficients are those specified in the vector
a.
sym2poly(a)
writes the vector of the specified polynomial coefficients (reverse operation to
the previous one).
roots(a)
gives the roots of the polynomial whose coefficients are the vector
a.
poly(v)
gives the polynomial whose roots are the components of the vector
v.
poly(A
) gives the characteristic polynomial matrix
A
.
polyder(a)
gives the vector
a
whose coefficients are the first derivative of the polynomial.
polyder(a, b)
gives the vector whose coefficients are the derivative of the polynomial
product of
a
and
b
.
[q, d] = polyder(a, b)
gives the coefficients of the numerator and denominator of the
derivative of the polynomial quotient
a/b.
polyval(p, x, S)
evaluates the polynomial
p
in x with standard deviation of the error
equal to
S.
