Since I'm on a mailing spree: how can I make a pd version of slide~ (MSP), which, according to the msp reference, is a logarithmic lowpass filter for smoothing envelops. Anything similar will do. I'm using vline~ for now to smooth out midi faders but it doesn't feel quite the same. 

And on a related subject: what is the best way to create an exponential signal ramp?

Many Thanks

Peiman