POLYVAL Evaluate polynomial.
Y = POLYVAL(P,X), when P is a vector of length N+1 whose elements
are the coefficients of a polynomial, is the value of the
polynomial evaluated at X.
Y = P(1)*X^N + P(2)*X^(N-1) + ... + P(N)*X + P(N+1)
If X is a matrix or vector, the polynomial is evaluated at all
points in X. See also POLYVALM for evaluation in a matrix sense.
Y = POLYVAL(P,X,[],MU) uses XHAT = (X-MU(1))/MU(2) in place of X.
The centering and scaling parameters MU are optional output
computed by POLYFIT.
[Y,DELTA] = POLYVAL(P,X,S) or [Y,DELTA] = POLYVAL(P,X,S,MU) uses
the optional output structure S provided 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.
See also POLYFIT, POLYVALM.