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The Moment Matrix is used to quantify errors in
experimental measurements.
- Often, the results of an experiments on
are
quoted in terms of means 
errors:
- These errors are standard deviations
.
- Now, this is throwing away information---the off diagonal terms
in M---which can be important.
- Thus, suppose some years after the experiment measures and
reports
, a theorist decides that particular linear
combinations 
(T an 
matrix) are useful.
- What are errors on y?
- To find diagonal terms in
---i.e., the errors
on our new
theorist's y---requires off diagonal terms in 
.
Geoffrey Fox, Northeast Parallel Architectures Center at Syracuse University, gcf@npac.syr.edu