Moving Average Rate Of Change

study(title="Moving Average Rate Of Change", shorttitle="MAROC")
sma_len = input(21, minval=1, title="SMA len")
roc_len = input(5, minval=1, title="ROC len")
src = close

smooth = sma(src, sma_len)
sma_roc = 100 * (smooth - smooth[roc_len])/smooth[roc_len]
color = sma_roc > sma_roc[roc_len] ? green : red

plot(sma_roc, color=color, title="SMA ROC", style=line)
hline(0)