Documentation/AlgoCode/Function reference
macdhist
MACD histogram (line − signal)
Reference/Oscillators/Function
macdhist(source, fast, slow, signal)
Positive when the MACD line is above its signal. Same arguments as macdline.
Return value
series
Short form: if the first argument is a number, Dovee uses close as the source.
Example
when macdhist() crosses above 0 then buy