The package mpc interfaces R to the C Library

    MPC, the Multiple Precision Complex Library
    -------------------------------------------

That is Free Software, available under the LGPL license.
See http://multiprecision.org/
    ----------------

MPC is itself built on and requires:

    GNU Multiple Precision Floating-Point Reliable Library (MPFR)
    http://www.mpfr.org

and:

    GNU Multiple Precision arithmetic library (GMP)
    http://gmplib.org


Most modern Unix operating systems provide a simple way to install MPC
and these two dependent libraries easily.

Under FreeBSD it is sufficient to simply type:

      pkg_add -r mpc

Under Debian and Ubuntu Linux distributions, it is sufficient to type:

      sudo apt-get install libmpc-dev

For MacOS X, downloading the source from the websites above and
compiling installing manually works fine, as does presumably the fink
or portinstall tools for Darwin/MacOS X.