Complex Gamma Function with Error Control An algorithm to compute the gamma function and log gamma function of a complex variable is presented. The standard algorithm is modified in several respects to insure the continuity of the function value and to reduce accumulation of round-off errors. In addition to computation of function values, this algorithm includes an object-time estimation of round-off errors. Experimental data with regard to the effectiveness of this error control are presented. A Fortran program for the algorithm appears in the algorithms section of this issue. CACM April, 1972 Kuki, H. complex gamma function, gamma function, complex log gamma function, loggamma function, round-off error control, inherent error control, run-time error estimates, error estimates 5.11 5.12 CA720407 JB January 31, 1978 12:59 PM 2366 4 2366 2364 5 2366 2366 5 2366 2366 5 2366 2366 5 2366 2366 6 2366