[pd] [noise~],[expr~], questions

[hard off]

sorry, i have a few questions today, i know it's bad from to ask them
all in one thread, but i don't want to start too many threads.


question 1)
how do you multiply a signal by a power of n ?  can you do it with expr~?

question 2)
is there a list of the functions that i can use with expr~ (and expr)
?  i have seen many of these functions in other peoples patches, but
can't find them in pd's documentation.

question 3)
i want to insert a percentage of random noise into a signal.  ie, for
every oscillation of an [osc~]  i want 25% of the samples to be
converted into noise.  the level and position of the noise should be
random, but 25% of the samples in each oscillation must be be
converted into noise.
any idea how to do that?

thanks for any help.