3BB

//@version=3

study(shorttitle="3BB", title="3 BollingerBands ", overlay=true)
length = input(20, minval=1)
src = input(close, title="Source")
mult = input(1.0, minval=0.001, maxval=50, title="Sgma1")
basis = sma(src, length)
dev = mult * stdev(src, length)
upper = basis + dev
lower = basis - dev

mult_2 = input(2.0, minval=0.001, maxval=50, title="Sgma2")
dev_2 = mult_2 * stdev(src, length)
upper_2 = basis + dev_2
lower_2 = basis - dev_2

mult_3 = input(3.0, minval=0.001, maxval=50, title="Sgma3")
dev_3 = mult_3 * stdev(src, length)
upper_3 = basis + dev_3
lower_3 = basis - dev_3

plot(basis, color=red,title="中心線")
p1 = plot(upper, color=blue,title="BB 1U")
p2 = plot(lower, color=blue,title="BB 1D")

p1_2 = plot(upper_2, color=blue,title="BB 2U")
p2_2 = plot(lower_2, color=blue,title="BB 2D")

p1_3 = plot(upper_3, color=blue,title="BB 3U")
p2_3 = plot(lower_3, color=blue,title="BB 3D")

fill(p1, p2, color=purple, title="BB 1", transp=95)
fill(p1_2, p2_2, color=blue, title="BB 2", transp=95)
fill(p1_3, p2_3, color=green, title="BB 3", transp=95)