pignisticdst.m

用于对DS证据理论进行Pignistic概率计算的函数

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%   The coryright belongs to Yang Yang,Automation Institute,NPU,710072
%   Xi'an, China      
%   EDITION NUMBER: 1.0
%   Contract me : E-mail [e-mail] ,
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%                 Home :   029-82375332
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function P=PignisticDST(e)
%   calculate the Pignistic Probalilities from bba m(.) in DST, the format is:
%   P=Pignistic(e)
%   e: evidences to be calculated,it is a vector for a  column.
%   P: output the Pignistic Probalilities from bba m(.),it have 2 elements
%      for two  class and 3 elements for three class ,the size is 1*n.
% Interpretion:
%   The function can only calculate two or three classes for the Frame
%   within DST.If the Frame have two elements,  they are denoted in
%   Theta={A,B},and if it  have three elements,the Theta={A,B,C}. Then the
%   2^Theta={0,A,B,A|B} for  two dimensions .  Then the Pignistic
%   Probalilities from bba m(.) in DST can be calculate in matrix .  

%   Note that the order of e must be set in the order of 2^Theta. 
%   Other Noting ,it has eight elements in the 2^Theta for three
%   class.

%   Do not hesitate to contract  me ,if you have any question.

[row,col]=size(e);
%Judge the classes of the Frame
if row==4
    class=2;
    elseif row==8
            class=3;  
    else disp(['The class number of the Frame is not two or three,the function can not be calculated']);
            return; 
end

if class==2
    P=[0,1,0,0.5;
       0,0,1,0.5]*e;
end
if class==3
   P=[0,1,0,1/2,0,1/2,0,1/3;
      0,0,1,1/2,0,0,1/2,1/3;
      0,0,0,0,1,1/2,1/2,1/3; ]*e; 
end