def gfsntc(target, fixref, method, abcorr, obsrvr, dref, dvec, crdsys, coord,
           relate, refval, adjust, step, nintvals,
           cnfine, result=None):
    """
    Determine time intervals for which a coordinate of an
    surface intercept position vector satisfies a numerical constraint.

    http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/gfsntc_c.html

    :param target: Name of the target body.
    :type target: str
    :param fixref: Body fixed frame associated with the target.
    :type fixref: str
    :param method: Name of method type for surface intercept calculation.
    :type method: str
    :param abcorr: Aberration correction flag
    :type abcorr: str
    :param obsrvr: Name of the observing body.
    :type obsrvr: str
    :param dref: Reference frame of direction vector of dvec.
    :type dref: str
    :param dvec: Pointing direction vector from the observer.
    :type dvec: 3-Element Array of floats
    :param crdsys: Name of the coordinate system containing COORD.
    :type crdsys: str
    :param coord: Name of the coordinate of interest
    :type coord: str
    :param relate: Relational operator.
    :type relate: str
    :param refval: Reference value.
    :type refval: float
    :param adjust: Absolute extremum adjustment value.
    :type adjust: float
    :param step: Step size in seconds for finding angular separation events.
    :type step: float
    :param nintvals: Workspace window interval count.
    :type nintvals: int
    :param cnfine: SPICE window to which the search is restricted.
    :type cnfine: spiceypy.utils.support_types.SpiceCell
    :param result: Optional SPICE window containing results.
    :type result: spiceypy.utils.support_types.SpiceCell
    """
    assert isinstance(cnfine, stypes.SpiceCell)
    assert cnfine.is_double()
    if result is None:
        result = stypes.SPICEDOUBLE_CELL(2000)
    else:
        assert isinstance(result, stypes.SpiceCell)
        assert result.is_double()
    target = stypes.stringToCharP(target)
    fixref = stypes.stringToCharP(fixref)
    method = stypes.stringToCharP(method)
    abcorr = stypes.stringToCharP(abcorr)
    obsrvr = stypes.stringToCharP(obsrvr)
    dref = stypes.stringToCharP(dref)
    dvec = stypes.toDoubleVector(dvec)
    crdsys = stypes.stringToCharP(crdsys)
    coord = stypes.stringToCharP(coord)
    relate = stypes.stringToCharP(relate)
    refval = ctypes.c_double(refval)
    adjust = ctypes.c_double(adjust)
    step = ctypes.c_double(step)
    nintvals = ctypes.c_int(nintvals)
    libspice.gfsntc_c(target, fixref, method, abcorr, obsrvr,
                      dref, dvec, crdsys, coord, relate, refval,
                      adjust, step, nintvals, ctypes.byref(cnfine),
                      ctypes.byref(result))
    return result
Determine time intervals for which a coordinate of an
    surface intercept position vector satisfies a numerical constraint.

    http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/gfsntc_c.html

    :param target: Name of the target body.
    :type target: str
    :param fixref: Body fixed frame associated with the target.
    :type fixref: str
    :param method: Name of method type for surface intercept calculation.
    :type method: str
    :param abcorr: Aberration correction flag
    :type abcorr: str
    :param obsrvr: Name of the observing body.
    :type obsrvr: str
    :param dref: Reference frame of direction vector of dvec.
    :type dref: str
    :param dvec: Pointing direction vector from the observer.
    :type dvec: 3-Element Array of floats
    :param crdsys: Name of the coordinate system containing COORD.
    :type crdsys: str
    :param coord: Name of the coordinate of interest
    :type coord: str
    :param relate: Relational operator.
    :type relate: str
    :param refval: Reference value.
    :type refval: float
    :param adjust: Absolute extremum adjustment value.
    :type adjust: float
    :param step: Step size in seconds for finding angular separation events.
    :type step: float
    :param nintvals: Workspace window interval count.
    :type nintvals: int
    :param cnfine: SPICE window to which the search is restricted.
    :type cnfine: spiceypy.utils.support_types.SpiceCell
    :param result: Optional SPICE window containing results.
    :type result: spiceypy.utils.support_types.SpiceCell