Single Timeframe EMA

study(title="Single Timeframe EMA", shorttitle="Single TF EMA", overlay=true)

len_ema_long = input(200, minval=1, title="Long Exponential Moving Average")
len_ema_mid = input(100, minval=1, title="Mid Exponential Moving Average")
len_ema_short = input(50, minval=1, title="Short Exponential Moving Average")
resCustom = input(title="Time interval (W, D, [min])", type=string, defval="D")

ema_long = security(tickerid, resCustom, ema(close, len_ema_long))
ema_mid = security(tickerid, resCustom, ema(close, len_ema_mid))
ema_short = security(tickerid, resCustom, ema(close, len_ema_short))
src = security(tickerid, resCustom, close)

s2 = cross(ema_long, ema_short) ? src : na
plot(ema_long, color=#FF9800, transp=0, linewidth=2)
plot(ema_mid, color=green, transp=0, linewidth=2)
plot(ema_short, color=#FF0000, transp=0, linewidth=2)