Aroon — how recently the window made its extreme, as a percentage of the
window.
highestbars answers "how many bars back is the high" as a negative
offset, 0 meaning the current bar. The whole study is that offset mapped
onto 0..100, so the sign convention is load-bearing: a fresh high gives
100 * (0 + length) / length = exactly 100, and a high at the far edge of
the window gives 0. Note the window is length + 1 bars, not length —
the reference counts the gaps between bars, not the bars.
Aroon — how recently the window made its extreme, as a percentage of the window.
highestbarsanswers "how many bars back is the high" as a negative offset,0meaning the current bar. The whole study is that offset mapped onto 0..100, so the sign convention is load-bearing: a fresh high gives100 * (0 + length) / length= exactly 100, and a high at the far edge of the window gives 0. Note the window islength + 1bars, notlength— the reference counts the gaps between bars, not the bars.