GAMMA(III)                   5/15/74                   GAMMA(III)







NAME

     gamma - log gamma function



SYNOPSIS

     jsr     pc,gamma



     double gamma(x)

     double x;



DESCRIPTION

     If x is passed (in fr0) gamma returns ln  |Γ(x)|  (in  fr0).

     The  sign  of  Γ(x)  is  returned  in  the  external integer

     signgam.  The following C program might be used to calculate

     Γ:



             y = gamma(x);

             if (y > 88.)

                     error( );

             y = exp(y);

             if(signgam)

                     y = -y;



DIAGNOSTICS

     The c-bit is set on  negative  integral  arguments  and  the

     maximum  value  is returned.  There is no error return for C

     programs.



BUGS

     No error return from C.