Support units specified in defined variables from Silo

I am not sure we support units for expressions in VisIt. However, Silo's DBPutDefvars call allows callers to define units for the expressions. A user has requested these be visible in VisIt just as units on ordinary variables are. This may or may not be a lot of work. We don't support units through expressions right now. We probably ought to. But, all that is needed to satisfy this is to ensure that whatever units the Silo file said should be associated with the RESULT of an expression should just be bound to them. So, it doesn't really require that expressions support units, just bind any units specified by the database upon completing the expression.

-----------------------REDMINE MIGRATION-----------------------
This ticket was migrated from Redmine. As such, not all
information was able to be captured in the transition. Below is
a complete record of the original redmine ticket.

Ticket number: 176
Status: Pending
Project: VisIt
Tracker: Feature
Priority: Normal
Subject: Support units specified in defined variables from Silo
Assigned to: -
Category: -
Target version: -
Author: Mark Miller
Start: 06/24/2010
Due date:
% Done: 0%
Estimated time: 8.00 hours
Created: 06/24/2010 04:59 pm
Updated: 07/06/2010 08:57 pm
Likelihood:
Severity:
Found in version: 2.12.3
Impact: 2 - Low
Expected Use: 3 - Occasional
OS: All
Support Group: Any
Description:
I am not sure we support units for expressions in VisIt. However, Silo's DBPutDefvars call allows callers to define units for the expressions. A user has requested these be visible in VisIt just as units on ordinary variables are. This may or may not be a lot of work. We don't support units through expressions right now. We probably ought to. But, all that is needed to satisfy this is to ensure that whatever units the Silo file said should be associated with the RESULT of an expression should just be bound to them. So, it doesn't really require that expressions support units, just bind any units specified by the database upon completing the expression.

Comments:

Start with Silo's DBPutDefvars metadata and the VisIt path that imports defined variables and completes expression results. Trace how units on ordinary variables are attached, then verify that units supplied for the expression result are preserved and visible in VisIt; no test or file is named in the issue.