[PD] round off the corners of a [line] movement?

[Peter P.]

Hi list,

often when I use [line¨] to make frequency glissandi, the point when the
ramp starts, and the point where it ends, appear as very sudden events
to my ears. I am wondering if there is an easy way to gradually speed up
the ramp when it starts, and slow it down before it reaches its target
value?
The only way I can think of so far is to model such a behavior with two
masses connected by an elastic link using the pmpd library. But a
vanilla way would be very interesting too!

Thanks in advance for all ideas and pointers!
cheersz, Peter