<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def isDiurnal(self):
 """ Returns true if this chart is diurnal. """

        sun = self.getObject(const.SUN)
        mc = self.getAngle(const.MC)
        
        # Get ecliptical positions and check if the
        # sun is above the horizon.
        lat = self.pos.lat
        sunRA, sunDecl = utils.eqCoords(sun.lon, sun.lat)
        mcRA, mcDecl = utils.eqCoords(mc.lon, 0)
        return utils.isAboveHorizon(sunRA, sunDecl, mcRA, lat)