undegradeBy doesn't work as expected

[jqueraltmo]

Using undegradeBy(0) in a pattern like $:s("bd*4").undegradeBy(0) should result in no sound being played, since no events should be "undegraded." However, the output is the same as $:s("bd*4").degradeBy(0), which plays all events as expected. This suggests that undegradeBy(0) is not behaving correctly.

The issue also occurs with other probability values. For example, s("bd*4").undegradeBy(0.2) appears to play "bd" approximately 80% of the time, which is the opposite of what the name suggests.

[yaxu]

I think this is expected behaviour - undegradeBy does the opposite of degradeBy.

[yaxu]

Please reopen if I'm missing something or the docs are unclear, thanks!

[jqueraltmo]

"Inverse of degradeBy: Randomly removes events from the pattern by a given amount. 0 = 100% chance of removal 1 = 0% chance of removal Events that would be removed by degradeBy are let through by undegradeBy and vice versa (see second example)."

0 = 100% chance of removal: undegradeBy(0) should produce no sound, but it plays all events.
0.2 = 80% chance of removal, but it plays 80% of the sounds, not the remaining 20%.

The problem is that undegradeBy is doing the same as degradeBy, not the opposite.

[yaxu]

Ah I see! This works as I expect and is the same as in tidal:

$: s("bd:4*4").undegradeBy(0.25)
$: s("bd:6*4").degradeBy(0.75)

But the description is wrong. As you say they both degrade by the given ratio, but will choose the opposite coin flip so when the ratios add up to 1, they never play the same event. I'm not sure how to explain this better!