void gfstep_c ( SpiceDouble time,
SpiceDouble * step )
Return the time step set by the most recent call to gfsstp_c.
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
time I Ignored ET value.
step O Time step to take.
time is an ignored double precision number. This argument
is present so the argument list of this routine is
compatible with the GF step size routine argument list
When this routine is called from within the GF
root-finding system, either the initial ET value of the
current interval of the confinement window, or the
value resulting from the last search step, is passed in
via the `time' argument.
step is the output step size. This is the value set by the
most recent call to gfsstp_c. Units are TDB seconds.
`step' is used in the GF search root-bracketing process.
`step' indicates how far to advance `time' so that `time' and
time+step may bracket a state transition and definitely
do not bracket more than one state transition.
1) If this routine is called before a step size has been
set via a call to gfsstp_c, the error SPICE(NOTINITIALIZED)
This routine returns the time step set by the most recent call to
1) User applications can pass gfstep_c to mid-level GF API routines
expecting a step size routine as an input argument. For
example, the GF API routine gfocce_c can be called as shown
in the code fragment below.
Select a twenty-second step. We'll ignore any occultations
lasting less than 20 seconds.
step = 20.0;
gfsstp_c ( step );
Perform the search.
gfocce_c ( "ANY",
"MOON", "ellipsoid", "IAU_MOON",
"SUN", "ellipsoid", "IAU_SUN",
"LT", "EARTH", CNVTOL,
gfstep_c, gfrefn_c, rpt,
gfrepi_c, gfrepu_c, gfrepf_c,
bail, gfbail_c, cnfine,
N.J. Bachman (JPL)
L.S. Elson (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
E.D. Wright (JPL)
-CSPICE Version 1.0.0, 15-APR-2009 (LSE) (NJB)
GF get constant step size