NUMERICAL-SOLUTION OF ALTARELLI-PARISI EQUATIONS

We discuss numerical solution of Altarelli-Parisi equations in a Lague rre-polynomial method and in a brute-force method. In the Laguerre met hod, we get good accuracy by taking about twenty Laguerre polynomials in the flavor-nonsinglet case. Excellent evolution results are obtaine d in the singlet case by taking only ten Laguerre polynomials. The acc uracy becomes slightly worse in the small and large x regions, especia lly in the nonsinglet case. These problems could be implemented by usi ng the brute-force method; however, running CPU time could be signific antly longer than the one in the Laguerre method.