.. index:: Policy Window

.. _Policy_Window:

Policy Window
=============

A policy window that displays the policies for a given :ref:`decision node<decision_node>`. If the node is instantiated then the policy is ignored and the policy window is disabled. Only policies with parent configurations of a non-zero probability are displayed. This is indicated by collapsing columns corresponding to parent configurations of zero probability, which happens e.g. when a parent node has evidence entered (see Figures 1 and 2).

See also :ref:`Single Policy Update<single_policy_update>`.

.. figure:: images/policywindow.png

	Figure 1: Example of a policy window for the node 'Drill' of the :ref:`oil wildcatter example<Oil_Wildcatter>`

.. figure:: images/policywindow1.png

	Figure 2: Example of a policy window for the node 'Drill' with zero-probability configurations collapsed. 
	*(Parent node is in state 'cl')*