clear, clc;
% This is an example for running the function mcLogisticR
%
% Problem:
%
% min - sum_{il} weight_{il} log( p_{il} ) + z * sum_j ||x^j||_q
%
% p_{il}= 1 / (1+ exp(-y_i (x_i' * a_i + c_l) ) ) denotes the probability
% weight_{il} is the weight for the i-th sample in the l-th classifier
% is a m x k matrix
% c_l is the intercept for the l-th classfier, and is a 1xk vector
% x_i denotes the i-th column of x
% x^j denotes the j-th row of x
% a_i' denotes the i-th row of A
%
% In this implementation, we assume weight_{il}=1/(mk)
%
% For detailed description of the function, please refer to the Manual.
%
%% ------------ History --------------------
% First version on August 10, 2009.
%
% September 5, 2009: adaptive line search is added
%
% For any problem, please contact Jun Liu (j.liu@asu.edu)
cd ..
cd ..
root=cd;
addpath(genpath([root '/SLEP']));
% add the functions in the folder SLEP to the path
% change to the original folder
cd Examples/L1Lq;
m=100; n=100; % The data matrix is of size m x n
k=10; % the number of classes (tasks)
q=2; % the value of q in the L1/Lq regularization
rho=0.4; % the regularization parameter
randNum=1; % a random number
% ---------------------- generate random data ----------------------
randn('state',(randNum-1)*3+1);
A=randn(m,n); % the data matrix
randn('state',(randNum-1)*3+2);
y=randn(m, k);
y=2* (y>0) - 1; % the response
%----------------------- Set optional items -----------------------
opts=[];
% Starting point
opts.init=2; % starting from a zero point
% Termination
opts.tFlag=5; % run .maxIter iterations
opts.maxIter=100; % maximum number of iterations
% Normalization
opts.nFlag=0; % without normalization
% Regularization
opts.rFlag=1; % the input parameter 'rho' is a ratio in (0, 1)
% Group Property
opts.q=q; % set the value for q
%----------------------- Run the code mcLogisticR -----------------------
fprintf('\n mFlag=0, lFlag=0 \n');
opts.mFlag=0; % treating it as compositive function
opts.lFlag=0; % Nemirovski's line search
tic;
[x1, c1, funVal1, ValueL1]= mcLogisticR(A, y, rho, opts);
toc;
opts.maxIter=1000;
fprintf('\n mFlag=1, lFlag=0 \n');
opts.mFlag=1; % smooth reformulation
opts.lFlag=0; % Nemirovski's line search
opts.tFlag=2; opts.tol= funVal1(end);
tic;
[x2, c2, funVal2, ValueL2]= mcLogisticR(A, y, rho, opts);
toc;
fprintf('\n mFlag=1, lFlag=1 \n');
opts.mFlag=1; % smooth reformulation
opts.lFlag=1; % adaptive line search
opts.tFlag=2; opts.tol= funVal1(end);
tic;
[x3, c3, funVal3, ValueL3]= mcLogisticR(A, y, rho, opts);
toc;
figure;
plot(funVal1,'-r');
hold on;
plot(funVal2,'--b');
hold on;
plot(funVal3,':g');
legend('mFlag=0, lFlag=0', 'mFlag=1, lFlag=0', 'mFlag=1, lFlag=1');
xlabel('Iteration (i)');
ylabel('The objective function value');
% % --------------------- compute the pathwise solutions ----------------
% opts.fName='mcLogisticR'; % set the function name to 'mcLogisticR'
% Z=[0.9, 0.8, 0.5, 0.3]; % set the parameters
%
% % run the function pathSolutionLogistic
% fprintf('\n Compute the pathwise solutions, please wait...');
% [X, C]=pathSolutionLogistic(A, y, Z, opts);