Is it possible for an array to somehow be used for smooth ramp ups and ramp downs of parameters?
What I'm thinking of is a method for cycling between 15hz and 8hz but so that it takes say an hour to get from 8hz to 15hz for instance?
like, how to use an array for stepping, so that there would be a glide going on where let's say you lower from 8.5hz to 8hz in 5 minutes, but then ramp up to 8.5hz back again in 15 minutes, and then for 25 minutes ramp up to 15hz? i would prefer to have this kind of control, but the milliseconds really throw me.

@esaruoho Like this?
slowarray.pd

The time and frequency arrays output floats in the range of 0-1 which are shifted to the desired range, for time it is 1-60 minutes by the [*1000]->[*60] and for frequency it is 8.5hz-17hz, [*8.5] to shift the 0-1 output of line to span 8.5 hz and [+8.5] to get it to run from 8.5hz up to 17hz.

Edit, error in the math for the time, should be {* 1000]->[* 60]->[* 60], first converts 0-1 to ms, second converts to seconds, third does minutes. lost a [* 60] somehow. Or you can just [* 3e+06] instead but I like to keep the math easy to read. Fixed the file but not the image.

If you pad the source array with 1 preceding point and 2 trailing points, tabread4~ can do it for free (not linearly, but it's nice).

Read the tabread4~ helpfile about those leading and trailing points.

hjh