bonk~ mask

Hi all. Been using MaxMSP a little while now but still learning. Currently I am developing a beat detection patch with it. I have used the likes of bonk~ with pleasing results.

However, I need to go further than just using bonk~, i need to effectively make my own bonk~ at a lower level.

Currently I have 6 reson~ objects whose squared outputs are summed and passed to a thresh~ object for detection.

However, in the Puckette paper and the bonk~ documentation it mentions the mask setting, I quoute:

"We defi ne a growth function as follows. For each
channel we maintain a mask m which represents the
current power in the channel. To accomplish this, af-
ter each analysis we look at the current power p. If
p > m we replace m by p; otherwise if m hasn't been
updated for more than masktime analyses (5 by de-
fault), the mask decays by multiplication by maskde-
cay (0.8)."

So my question is; any idea how to implement this in Max?

Any help would be extremely appreciated!

Dan