Normally you modify a node using the node properties dialog box, which allows you to change any of the properties of a single node. However, sometimes you want to make the same change to several nodes at once. With Netica, you can add, remove, rename or reorder states, change discretization thresholds, enter findings, enter user-defined fields, change node-sets, etc. to as many nodes as wish, with one operation.
How To: Select the desired nodes, right-click on one of them, and make a choice from the menu. Any choice you make will apply to all the nodes, except for the choices: Select, Deselect and Properties.
Entering Findings: When several nodes are selected and you right-click on one and choose Enter Findings, you will be presented with a menu that lists all the states of all the nodes selected, with any findings already entered having check-marks. If you choose a state from the list, then every node having that state will get it entered as a finding, while the other selected nodes will not have their finding changed. If you want the other findings removed, then you should first choose Enter Finding → Unknown (Retract), and then the desired finding. If the selected nodes are continuous nodes, then you can enter a numeric finding for them all simultaneously using Enter Finding → Numeric Value.
Setting States: There are 4 choices for changing the states of a node available from the Modify submenu: Add State, Delete State, Rename State and Set States. The first 3 are fairly straightforward; they adjust all effected CPTs to produce the least disturbance possible. In the case of Add State and Rename state inference results will not be effected at all. Set States has the more complex behaviour:
• If the new states have exactly the same names as the old ones, and there is the same number of them, but just in a different order, it re-orders the states and all related structures (such as state numbers and CPTs), so that all inference results will be unaffected.
• Otherwise, if there are the same number of states, it just renames the states (so inference results will be unaffected).
Warning: If there are a different number of states, all related structures (such as state numbers, state titles and CPTs) are removed, which of course will effect inference results. If you want to keep the tables, then you need to use Modify → Add State or Modify → Delete State instead.
User-Defined Fields: As described
on the right-clicking page, you can
set user fields of a node by right-clicking and choosing Modify→ User Defined.
If you click on one of several selected nodes, then a menu will
appear listing all the fields already defined for at least one of the
selected nodes. By choosing a field, you can set its value. If
the field was originally defined for only some of the nodes, Netica will
ask you if you want to change the value of only those nodes, or whether
you want to add the field to all the nodes. If you make a field
empty, Netica will ask you whether you want it to represent an empty field,
or if you want the field removed, which you can use to remove fields from
a large set of nodes at once. Likewise, you can add a field to a
large number of nodes by choosing Modify
→ User
Defined → Enter,
and then entering the name of the new field.