Scilab Function
Last update : 28/12/2008
roots - roots of polynomials
Calling Sequence
- [x]=roots(p)
- [x]=roots(p,'e')
Parameters
-
p: polynomial with real or complex coefficients or vector of the
polynomial coefficients in decreasing degree order (Matlab
compatibility).
Description
x=roots(p) returns in the complex vector x the roots of the
polynomial p. For real polynomials of degree <=100 the fast
RPOLY algorithm is used. In the other cases the roots are computed as the
eigenvalues of the associated companion matrix. Use
x=roots(p,'e') to force this algorithm in any cases.
Examples
p=poly([0,10,1+%i,1-%i],'x');
roots(p)
A=rand(3,3);roots(poly(A,'x')) // Evals by characteristic polynomial
spec(A)
See Also
poly, spec, companion,
Authors
-
Serge Steer (INRIA)
Bibliography
The RPOLY algorithm is described in ACM TOMS 1 (1975) 178-189Used Function
The rpoly.f source codes can be found in the directory routines/control
of a Scilab source distribution. The
eigenvalue computation is perfomed using DGEEV and ZGEEV LAPACK codes.