def connect(self): 
        try:
            self.connection = pymongo.Connection(self.host, self.port)
            self.db = self.connection[self.name]
        except AutoReconnect:
            raise DatabaseException("It's not possible connect to the database")
def winding_flux(pos, flux, ax=0):
    """plot flux vs position"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Winding Flux / Vs')
    ax.grid(True)
    for p, f in zip(pos, flux):
        ax.plot(p, f)