S_MAIN.m

% This script performs ranking allocation using the 
% Entropy-Pooling approach by Attilio Meucci, as it appears in 
% "A. Meucci - Fully Flexible Views: Theory and Practice -
% The Risk Magazine, October 2008, p 100-106"
% available at www.symmys.com > Research > Working Papers

% Code by A. Meucci, September 2008
% Last version available at www.symmys.com > Teaching > MATLAB

clear; clc; close all
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% Load panel X of joint returns realizations and vector p of respective probabilities
% In real life, these are provided by the estimation process
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load 'ReturnsDistribution.mat'; % 

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% compute and plot efficient frontier based on prior market distribution
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Options.NumPortf=20; % number of portfolios in efficient frontier
Options.FrontierSpan=[.3 .9]; % range of normalized exp.vals. spanned by efficient frontier

[e,s,w,M,S] = EfficientFrontier(X,p,Options);
PlotResults(e,s,w,M)

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% process ordering information (this is the core of the Entropy Pooling approach
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% the expected return of each entry of Lower is supposed to be smaller than respective entry in Upper
Lower=[4];  
Upper=[3];
p_ = ViewRanking(X,p,Lower,Upper); 

%confidence
c=.5; 
p_=(1-c)*p+c*p_;

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% compute and plot efficient frontier based on posterior market distribution
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[e_,s_,w_,M_,S_] = EfficientFrontier(X,p_,Options);
PlotResults(e_,s_,w_,M_,Lower,Upper)