# indie:lang_version = 5
from indie import indicator, param, source, plot, color
from indie.algorithms import Ema


@indicator('TEMA', overlay_main_pane=True)  # Triple EMA
@param.int('length', default=9, min=1)
@param.source('src', default=source.CLOSE, title='Source')
@plot.line(color=color.BLUE)
def Main(self, length, src):
    ema1 = Ema.new(src, length)
    ema2 = Ema.new(ema1, length)
    ema3 = Ema.new(ema2, length)
    return 3 * (ema1[0] - ema2[0]) + ema3[0]