I notice that if you go to the above example code and you look at the code in lines 96 and 97 a ema class is initialized without using the self notation. Thus far whenever I've wanted to use an indicator I would for example do the following : self.ema(symbol,duration, resolution). But from what I've seen you don't use self.ema when filtering your coarse universe. 


I've noticed here to initialize your ema class all you need is the duration and the naming convention is ExponentialMovingAverage as opppose to >>>> self.EMA. Lets say I wanted to look at other examples of indicators I could use without having to use the self notation where would I look ? I want to create a universe of sercurites where all of the securities have an adx reading above 30.