Contents Previous Next Subchapters

Using Laguerre's Method to Find The Roots of a Polynomial
Syntax pol2zero(p)
See Also polval , pol2asc

Description
Returns a complex column vector that contains the roots of the polynomial corresponding to the real, double-precision or complex column vector p. If v is a column vector of length n the corresponding polynomial v[x] is
                      1        2              n-1
     v[x] = v  +  v  x  +  v  x   + ... + v  x
             1     2        3              n
If z is the return value, it has one fewer elements than p and p[x] evaluated at x = z(i) is zero for each i.

Example
The roots of the polynomial
      2
     x  -  1
are -1 and +1. If you enter
     p = {-1., 0., 1.}
     pol2zero(p)
O-Matrix will reply
     {
     (-1, 0)
     (1, 0)
     }
or it will reply
     {
     (1, 0)
     (-1, 0)
     }
because the order of the roots is not determined.

Exceptions
If the method fails, the return value has type equal to "novalue". This should be a very rare case.