reloading a non dynamic subset encounters error if core has not already been found

[Jwely]

the way dynamic data is tossed out before pickling creates problems if the core has not already been found prior to pickling. This was probably introduced when the core finding method was refined to iteratively solve for the core location while slowly narrowing the search field if characteristics were outside the reasonable range.

[Jwely]

this has been resolved by simply ensuring the right functions are run upon computation from raw vector files to make sure the right attributes are all already populated.