Displaying 3 results from an estimated 3 matches for "polyval".
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pol_val
2004 Aug 09
1
returns the value of a polynomial of degree n evaluated at x.
> Background:
> OS: Linux Mandrake 9.1
> release: R 1.9.0
> editor: Xemacs 21.4
> frontend: ESS 5.1.23
> ---------------------------------
>
> Colleagues
>
Is there a function in R that is similar to polyval in matlab? (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).
<http://www.mathworks.com/access/helpdesk/help/techdoc/ref/polyva...
2007 Aug 15
1
Polynomial fitting
...ients of a
polynomial p(x) of degree m that fits the data, p(x[i]) to y[i], in a
least squares sense. The result c is a vector of length m+1 containing
the polynomial coefficients in descending powers:
p(x) = c[1]*x^n + c[2]*x^(n-1) + ... + c[n]*x + c[n+1]
For prediction, one can then use function polyval like the following:
y0 = polyval( polyfit( x, y, degree ), x0 )
y0 are the prediction values at points x0 using the given polynomial.
In R, we know there is lm for 1-degree polynomial:
lm( y ~ x ) == polyfit( x, y, 1 )
and for prediction I can just create a function like:
lsqfit <- function(...
2004 Aug 09
0
returns the value of a polynomial of degree n evaluated a t x.
...(PIRSA-SARDI)
>
> > Background:
> > OS: Linux Mandrake 9.1
> > release: R 1.9.0
> > editor: Xemacs 21.4
> > frontend: ESS 5.1.23
> > ---------------------------------
> >
> > Colleagues
> >
> Is there a function in R that is similar to polyval in matlab? (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).
> <http://www.mathworks.com/access/helpde...