Creating tree views and tree slices

Tree view

Given a node list we can create a new tree by calling pysjef.tree_view(). It recursively follows the parents until a desired root, and returns corresponding list of roots.

This effectively creates views of the global tree which contain specified nodes.

Tree slicing

Slices of the tree can be obtained by using to select a set of nodes and using pysjef.tree_view() to recreate the tree.

This mechanism is already part of and can be used by specifying return_option argument.