Smoothed Moving Average Crossover scan (TOS)

Wow, spent way to much time on this. This one really took me down a rabbit hole. Almost didn’t make it back out.

So I found that TradingView has this SMMA as a built in study. I’ve worked with that code before and it was super easy to port that over to Thinkorswim. Only problem, the charts didn’t match. Even after I updated the code to match the formula found in the link you provided, no match. I was about to throw in the towel and decided to do a quick Google search and found this: https://futures.io/ninjatrader-programming/8358-smoothed-moving-average-smma-how-avoid.html

It basically describes someone else trying to get this thing working on the NinjaTrader platform. Eventually they decide this SMMA is only good for the garbage bin (their words, not mine). In this post they describe one version was very close to an exponential moving average. Well that got me thinking.

So I ran through all the different types of moving averages available on Thinkorswim. When I got to the Wilders Smoothing I found an exact match for the SMMA on TradingView.com. I have no idea if this matches the SMMA on other platforms. But from that post on futures.io I gather this SMMA varies from platform to platform. If it does, stay away. Far, far away.

Before presenting the code I will mention that in your clarification you stated you wanted to scan for the 8 SMMA crossing above the 4 SMMA. When defining moving average crossovers the industry standard lexicon is to always define the shorter moving average crossing the longer moving average. In the code provided here, I define a crossAbove as being when the 4 period moving average crosses above the 8 period moving average.

So, here is my solution to your question, using Wilders Smoothing in place of the failed code for the SMMA:

#
# TD Ameritrade IP Company, Inc. (c) 2008-2017
#
input price = close;
input length1 = 4;
input length2 = 8;
input barsAfterCross = 3;
def ws1 = WildersAverage(price, length1);
def ws2 = WildersAverage(price, length2);
def crossAbove = ws1[1] < ws2[1] and ws1 > ws2;
def crossBelow = ws1[1] > ws2[1] and ws1 < ws2; # use this to scan for ws1 crossing above ws2 plot scan = crossAbove[barsAfterCross - 1] and ws1 > ws2;
# use this to scan for ws1 crossing below ws2
#plot scan = crossBelow[barsAfterCross - 1] and ws1 < ws2;