=ADD= =reftype= 14 =number= 97-18 =url= ftp://ftp.risc.uni-linz.ac.at/pub/techreports/1997/97-18.ps.gz =year= 1997 =author= Moritsugu; Shiuchi + Kuriyama; Kazuko =title= Fraction-free Method for Computing Rational Normal Forms of Polynomial Matrices =month= 06 =abstract= In this paper, we present a fraction-free algorithm for computing rational normal forms of matrices with univariate polynomial entries. In the traditional algorithm based on Danilevskii's method, its principal transformations are similar to Gaussian elimination. When they are carried out exactly by computer algebra system, the elements of intermediate matrices extremely swell and it requires much CPU-time to compute g.c.d.s of polynomials for reducing rational expressions. \par In order to avoid such difficulty, we give a fraction-free algorithm analogous to Bareiss' single-step fraction-free elimination. We have implemented it on the computer algebra system Reduce3.5. The experimental result shows the efficiency of our algorithm. =location= 2 =owner= 2 =source= 3