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 |
© 1994-2005 The MathWorks, Inc.