CARRTIME(3)

NAME

     carrtime, Ctime - compute Carrington time

SYNOPSIS

     TIME carrtime(Ct,Crot,Clong)
      TIME *Ct;
      int  *Crot, *Clong;

     TIME Ctime(crot, clong)
     int crot, clong;

DESCRIPTION

     Carrtime takes pointers to times and  Carrington  times  and
     returns  a Carrington time.  Ctime takes simple integers for
     the Carrington rotation and longitude and returns  the  Car-
     rington time.  Both functions update the curtime structure.

     The return value of this function is always the  appropriate
     Carrington  time.   In  every case date() is called with the
     corresponding value of the standard time.

     Calculations are completed with the following priority:

     If Ct == NULL (0) the remaining quantities will be  computed
     from the DATE structure value for currtime._time.

     If *Ct != 0.0 the remaining quantities will be computed from
     it.

     If *Crot and *Clong != 0 then the unknowns  will  be  calcu-
     lated from them.

     If *Ct, *Crot, and *Clong = 0 then  they  will  be  computed
     from the DATE structure curtime.

FILES

     /usr/local/lib/libdate.a
     /usr/src/local/date/carrtime.c
     /usr/man/manl/carrtime.l

SEE ALSO

     date(3)

DIAGNOSTICS

     none

BUGS

     Since the Earth's orbit is an ellipse,  carrington  time  is
     not  really  a  linear  function  of standard time.  This is
     ignored here.  See solephem for a more accurate  computation
     from StdT -> CT.