Find zeros of a real or complex polynomial.

1 | ```
polyroot(z)
``` |

`z` |
the vector of polynomial coefficients in increasing order. |

A polynomial of degree *n - 1*,

*
p(x) = z1 + z2 * x + … + z[n] * x^(n-1)*

is given by its coefficient vector `z[1:n]`

.
`polyroot`

returns the *n-1* complex zeros of *p(x)*
using the Jenkins-Traub algorithm.

If the coefficient vector `z`

has zeroes for the highest powers,
these are discarded.

There is no maximum degree, but numerical stability may be an issue for all but low-degree polynomials.

A complex vector of length *n - 1*, where *n* is the position
of the largest non-zero element of `z`

.

C translation by Ross Ihaka of Fortran code in the reference, with modifications by the R Core Team.

Jenkins, M. A. and Traub, J. F. (1972).
Algorithm 419: zeros of a complex polynomial.
*Communications of the ACM*, **15**(2), 97–99.
\Sexpr[results=rd,stage=build]{tools:::Rd_expr_doi("10.1145/361254.361262")}.

`uniroot`

for numerical root finding of arbitrary
functions;
`complex`

and the `zero`

example in the demos
directory.

1 2 3 4 |

What can we improve?

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.

Close