ComputeAlpha_j_a_o
PURPOSE 
Computes a particular alpha-element.
SYNOPSIS
function alpha_j_a_o=ComputeAlpha_j_a_o(P,V,j,a,o)
DESCRIPTION
Computes a particular alpha-element.
Computes a single alpha_j_a_o element as described in Section 3.1
equation (6), but particularized for discrete state spaces.
This function can be used when pre-computing the set of all alpha_j_a_o
elements before the backup operation or when computing only one of
them during the backup.
Parameters
P: The POMDP
V: The previous policy/value function/set of alpha-elements.
j: Index of the previous alpha element to use.
a: Index of the action to use.
o: Index of the observation to use.CROSS-REFERENCE INFORMATION
This function calls:
- GetActionModelFixedA Returns the action model for a given action.
- GetActionModelFixedA Returns the action model for a given action.
- GetActionModelFixedA Returns the action model for a given action.
- GetActionModelFixedA Returns the action model for a given action.
- get Get for GBeliefs.
- get Get function for the GMixture object.
- get Gaussian object get function.
- GetObsModelFixedO Defines p(o|s) for a fixed 'o'.
- GetObsModelFixedO Defines p(o|s) for a fixed 'o'.
- GetObsModelFixedO Defines p(s|o).
- GetObsModelFixedO Defines p(s|o).
- get Get function for CS_CO_CA_POMDPs.
- get Get function for CS_CO_DA_POMDPs.
- get Get function for CS_CO_POMDPs.
- get Get function for CS_DO_CA_POMDPs.
- get Get function for CS_DO_DA_POMDPs.
- get Get function for CS_POMDPs.
- get Get function for DS_CO_CA_POMDPs.
- get Get function for DS_CO_DA_POMDPs.
- get Get function for DS_DO_CA_POMDPs.
- get Get function for DS_DO_DA_POMDPs.
- get Get functio for POMDPs.
- dim Dimensionality of a continuous space.
- dim Dimensionality of a discrete space.
- ComputeAlpha_a Compute the alpha_i_n-element for the given action and belief.
- ComputeAlpha_a Compute the alpha_i_n-element for the given action and belief.
- ComputeAlpha_a Compute the alpha_i_n-element for the given action and belief.
- ComputeAlphas_j_a_o Computes the set of al possible alpha-elements.
SOURCE CODE
0001 function alpha_j_a_o=ComputeAlpha_j_a_o(P,V,j,a,o) 0002 % Computes a particular alpha-element. 0003 % 0004 % Computes a single alpha_j_a_o element as described in Section 3.1 0005 % equation (6), but particularized for discrete state spaces. 0006 % 0007 % This function can be used when pre-computing the set of all alpha_j_a_o 0008 % elements before the backup operation or when computing only one of 0009 % them during the backup. 0010 % 0011 % Parameters 0012 % P: The POMDP 0013 % V: The previous policy/value function/set of alpha-elements. 0014 % j: Index of the previous alpha element to use. 0015 % a: Index of the action to use. 0016 % o: Index of the observation to use. 0017 0018 S=get(P,'StateSpace'); 0019 ns=dim(S); 0020 p_s1_a_s=GetActionModelFixedA(P,a); 0021 p_o_s1=GetObsModelFixedO(P,o); 0022 alpha_j_a_o=full(sum(repmat(V{j}.*p_o_s1,1,ns).*p_s1_a_s,1)'); 0023 0024