IMPLEMENTING COMPLEX ELEMENTARY-FUNCTIONS USING EXCEPTION HANDLING

Algorithms are developed for reliable and accurate evaluations of the complex elementary functions required in FORTRAN 77 and FORTRAN 90, na mely, cabs, csqrt, cexp, clog, csin, and ccos. The algorithms are pres ented in a pseudocode that has a convenient exception-handling facilit y. A tight error bound is derived for each algorithm. Corresponding FO RTRAN programs for an IEEE environment have also been developed to ill ustrate the practicality of the algorithms, and these programs have be en tested very carefully to help confirm the correctness of the algori thms and their error bounds. The results of these tests are included i n the paper, but the FORTRAN programs are not; the programs are availa ble from Fairgrieve (tff@cs.toronto.edu).