| MATLAB Function Reference | |
Syntax
Description
y = polyval(p,x)
returns the value of a polynomial of degree n evaluated at x. The input argument p is a vector of length n+1 whose elements are the coefficients in descending powers of the polynomial to be evaluated.
x can be a matrix or a vector. In either case, polyval evaluates p at each element of x.
y = polyval(p,x,[],mu)
uses 
in place of 
. In this equation, 
and 
. The centering and scaling parameters mu = are optional output computed by 
polyfit.
[y,delta] = polyval(p,x,S) and [y,delta] = polyval(p,x,S,mu)
use the optional output structure S generated by polyfit to generate error estimates, y±delta. If the errors in the data input to polyfit are independent normal with constant variance, y±delta contains at least 50% of the predictions.
Remarks
The polyvalm(p,x) function, with x a matrix, evaluates the polynomial in a matrix sense. See polyvalm for more information.
Examples
The polynomial 
is evaluated at 
= 5, 7, and 9 with
For another example, see polyfit.
See Also
| | polyint | polyvalm | |