The Quick & Dirty Partition Mode How to Guide

Carafe output is in this font.
Needed input is in bold.

carafe> big extract mycircuit.gds gds
This will start partition mode circuit extraction by determining the bounding box of the circuit. Once that is done you'll be prompted:

Cell mycircuit bounding box: ll: (-75000, -50000) ur: (88000, 181000)
Enter partition size (width height) in centimicrons : 50000 90000 
You give it the partition size: width height and it will extract on it's merry way.

If you know the bounding box ahead of time (maybe you ran big option bbox...) Or if you have a feel for partition sizes, you can set the partition size before you extract by using:

carafe> big option partitionsize 50000 90000
And then run the big extract command.

If you really do know the bounding box, you can tell it that ahead of time too:

carafe> big option bbox -75000 50000 88000 181000
And if you are using a gds file (as opposed to a mag file...) you need to tell it the top level cell name if you gave it the bounding box:
carafe> big option gdstoplevel MYCIRCUIT
Then you can run:
carafe> big extract mycircuit.gds gds
Without any extra input needed.