D.7.2.5 interpolate
...................
Procedure from library solve.lib (see solve_lib).

Usage:
interpolate(p,v,d); p,v=ideals of numbers, d=integer

Assume:
Ground field K is the field of rational numbers, p and v are lists
of elements of the ground field K with p[j] != -1,0,1, size(p) = n
(= number of vars) and size(v)=N=(d+1)^n.

Return:
poly f, the unique polynomial f of degree n*d with prescribed values
v[i] at the points p(i)=(p[1]^(i-1),..,p[n]^(i-1)), i=1,..,N.

Note:
mainly useful when n=1, i.e. f is satisfying f(p^(i-1)) = v[i],
i=1..d+1.

Example:
LIB "solve.lib";
ring r1 = 0,(x),lp;
// determine f with deg(f) = 4 and
// v = values of f at points 3^0, 3^1, 3^2, 3^3, 3^4
ideal v=16,0,11376,1046880,85949136;
interpolate( 3, v, 4 );
==> 2x4-22x2+36
See also:
vandermonde.


<font size="-1">
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; User manual for <a href="http://www.singular.uni-kl.de/"><i>Singular</i></a> version 2-0-4, October 2002,
generated by <a href="http://www.gnu.org/software/texinfo/"><i>texi2html</i></a>.
</font>

</body>
</html>
