Trigrams

// This source code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/

//@version=4
study("Trigrams", overlay=true)

bullish = close > open
bearish = close < open

body = abs(open-close)
lowerShadow = min(open,close)-low
upperShadow  = high-max(close,open)
range = high-low

///Trigram Conditions
/// Source: https://www.aguba.net/gupiao/10113.html
Heaven = bearish and abs(high - open) < 0.2*body and abs(low - close) < 0.2*body
Earth = bullish and abs(high - close)  < 0.2*body and abs(low - open) < 0.2*body
Water = bullish and  upperShadow >= 1.5*body  and upperShadow > 1.7 * lowerShadow
Mountain = bullish and lowerShadow >= 1.5*body  and lowerShadow > 1.7 * upperShadow
Flame = bearish and lowerShadow >= 1.5*body  and lowerShadow > 1.7 * upperShadow
Lake = bearish and upperShadow >= 1.5*body  and upperShadow > 1.7 * lowerShadow

Thunder = false
Wind = false
if (not Heaven and not Earth and not Water and not Mountain and not Flame and not Lake)
    Thunder := bearish and high > open and low < close
    Wind := bullish and high > close and low < open

///Plot the Trigrams
plotchar(Heaven, char='☰', location=location.abovebar, color=color.white)
plotchar(Earth, char='☷', location=location.abovebar, color=color.black)
plotchar(Thunder, char='☳', location=location.abovebar, color=color.yellow)
plotchar(Water, char='☵' ,location=location.abovebar, color=color.aqua)
plotchar(Mountain, char='☶', location=location.abovebar, color=color.maroon)
plotchar(Wind, char='☴' ,location=location.abovebar, color=color.green)
plotchar(Flame, char='☲' ,location=location.abovebar, color=color.red)
plotchar(Lake, char='☱' ,location=location.abovebar, color=color.gray)