This object records the (symmetric)
matrix of correlation coefficients
between parameters in the most recent least squares fit. There can
at most one of these; it is automatically created if not present
updated on every fit.
This is used
to estimate the uncertainty in calculated line positions,
provided ShowEstUnc is set at
top level. It can be edited in the constants
window. To add or remove entries right click on the
label and select resync;
this will adjust the matrix so that every parameter marked as
floated has a corresponding row and column in the matrix.
For compatibility reasons the correlations object was only written
the .pgo file in versions 8 and before if ShowEstUnc was set.