[MetaCRS] Tolerance values in standard test format

[Martin Davis]

Is the notion of "tolerance" actually conflating two different requiremts?
 
1. Capture the accuracy of the test data as supplied from some external 
source.
2. Indicate the expected accuracy of a given implementation of a 
projection operation. 

#1 needs to be specified externally, obviously.  Possibly it could be 
indicated by the supplied precision of the expected value?

#2 would seem to be library dependent.

The definition of tolerance seems to be getting quite complex.  As Frank 
says, it wouild be nice to move ahead with creating test artifacts even 
if the tolerance issue is not completely settled.

-- 
Martin Davis
Senior Technical Architect
Refractions Research, Inc.
(250) 383-3022