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 5.2
pages 15 and 16 of the paper.
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.
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 5.2
0005 % pages 15 and 16 of the paper.
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 p_o_s1=GetObsModelFixedO(P,o);
0019 ifget(p_o_s1,'n')==0
0020 alpha_j_a_o=GMixture();
0021 else
0022 p_s1_a_s=GetActionModelFixedA(P,a); %Gaussian on the varS given a
0023 alpha_j_a_o=Compress(Compose(V{j}*p_o_s1,-p_s1_a_s),P.maxAlphaC);
0024 end