Thanks, that works, but also would like to make the slide happen over 1 second, not instantaneously.

This tells how to make pitchbend in bytes, but I need to make them according to the pic.

MIDI Tutorial Part 8 - Pitch Bend
The Pitch Bend message is used to vary the pitch of the notes that are playing on the current MIDI channel. The message is the following:

Status byte : 1110 CCCC
Data byte 1 ...

I want to experiment with alternative tunings, so I need to be able to make notes with exact pitch.
I can get a float from a poly, but not backwards.

ps I am new to ask questions online, don't hesitate to tell me if I am wrong