bairstow

what is it?

this is Fortran program that factors given real polynomial into second degree polynomials using Bairstow’s method (that is, guess the factor, divide by it, and hope that the result is zero polynomial. it isn’t? apply newton method)

what is it good for?

it’s good if you have a high degree polynomial, you want to find its zeros, and somehow you don’t want to use any of the hundreds of available tools.

does it work?

kind of. you need to edit paths to lapack and blas in makefile, and i only compiled it with intel fortran. it does not have any useful interface, and i tested it only with a handful of polynomials.

usage

just run it, input is hardcoded (no, i’m not joking. no, i don’t care).

license

do with it whatever you want, i’ll be happy if you let me know that you find it interesting (maybe you do), or that you use it (wow, what for?)

author

Adam Michalik <adamm@mimuw.edu.pl>