Ma crossover code

[Luandre Ezra]

Hi guys, I've found this video about how to code moving average crossover. I want to know why it needs the previous candle crossover (lastSlowMovingAv erage and lastFastMovingAverage variable in the video) to make the code works?

[William Roeder]

A cross is an X, four end points.

double aPrev = …, aCurr = …,
       bPrev = …, bCurr = …;
bool   wasUp = aPrev > bPrev,
        isUp = aCurr > bCurr,
       isCross = isUp != wasUp;

How would you test for a cross with two? Slow<Fast is considered an uptrend (one or many bars.) It isn't cross.