How to use variables in MongoDB Map-reduce map function

Question

Given a document

{_id:110000, groupings:{A:\'AV\',B:\'BV\',C:\'CV\',D:\'DV\'},coin:{old:10,new:12}}

My specs call for the specification of

Answer 1

You can pass global, read-only data into map-reduce functions using the "scope" parameter on the map-reduce command. It's not very well documented, I'm afraid.