function varargout = MarkovTool(varargin)
% Last Modified by GUIDE v2.5 23-Aug-2006 12:06:54

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @MarkovTool_OpeningFcn, ...
                   'gui_OutputFcn',  @MarkovTool_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before MarkovTool is made visible.
function MarkovTool_OpeningFcn(hObject, eventdata, handles, varargin)

global prob_a prob_b prob_state; 
global precision n;

%No more than 3 digits
n = 3;
precision = 10^n;
 
prob_a = 0.5;
prob_b = 0.5;
prob_state = 0.5;

% Choose default command line output for MarkovTool
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes MarkovTool wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = MarkovTool_OutputFcn(hObject, eventdata, handles) 
varargout{1} = handles.output;

% --- Executes on slider movement.
function ProbASlider_Callback(hObject, eventdata, handles)

global prob_a;
global precision;

prob_a = round(precision*get(handles.ProbASlider,'Value'))/precision;
set(handles.CondProbA,'String',num2str(prob_a));
set(handles.warningA, 'String', strcat('Updated value of P(A|A):', num2str(prob_a)));

% --- Executes during object creation, after setting all properties.
function ProbASlider_CreateFcn(hObject, eventdata, handles)

global prob_a;

% Hint: slider controls usually have a light gray background.
if isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor',[.9 .9 .9]);
end

set(hObject,'Value',prob_a)

% --- Executes on slider movement.
function ProbBSlider_Callback(hObject, eventdata, handles)

global prob_b;
global precision;

prob_b = round(precision*get(handles.ProbBSlider,'Value'))/precision;
set(handles.CondProbB,'String',num2str(prob_b));
set(handles.warningB, 'String', strcat('Updated value of P(B|B):', num2str(prob_b)));

% --- Executes during object creation, after setting all properties.
function ProbBSlider_CreateFcn(hObject, eventdata, handles)

global prob_b;

% Hint: slider controls usually have a light gray background.
if isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor',[.9 .9 .9]);
end

set(hObject,'Value',prob_b);

% --- Executes on slider movement.
function StateSlider_Callback(hObject, eventdata, handles)

global prob_state;
global precision;

prob_state = round(precision*get(handles.StateSlider,'Value'))/precision;
set(handles.StateInitial,'String',num2str(prob_state));
set(handles.warningState, 'String', strcat('Updated value of StateInit:', num2str(prob_state)));

% --- Executes during object creation, after setting all properties.
function StateSlider_CreateFcn(hObject, eventdata, handles)

global prob_state;

if isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor',[.9 .9 .9]);
end

set(hObject,'Value',prob_state);

function CondProbA_Callback(hObject, eventdata, handles)

global prob_a precision;

temp_str = get(handles.CondProbA,'String');
temp = str2double(temp_str);

if (isempty(temp) || (temp < 0) || isnan(temp) || (temp > 1) || ~isreal(temp)) % the input is invalid
    set(handles.warningA, 'String', ...
    strcat('INVALID INPUT for P(A|A):',temp_str, '. Current value: ',...
    num2str(prob_a)));
else
    prob_a = round(precision*temp)/precision;
    set(handles.warningA, 'String', strcat('Updated value of P(A|A):', num2str(prob_a)));
    set(handles.CondProbA, 'String', num2str(prob_a));
    set(handles.ProbASlider, 'Value', prob_a);
end

% --- Executes during object creation, after setting all properties.
function CondProbA_CreateFcn(hObject, eventdata, handles)

global prob_a;

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

set(hObject, 'String', num2str(prob_a));

function CondProbB_Callback(hObject, eventdata, handles)

global prob_b precision;

temp_str = get(handles.CondProbB,'String');
temp = str2double(temp_str);

if (isempty(temp) || (temp < 0) || isnan(temp) || (temp > 1) || ~isreal(temp)) % the input is invalid
    set(handles.warningB, 'String', ...
    strcat('INVALID INPUT for P(B|B):',temp_str, '. Current value: ',...
    num2str(prob_b)));
else
    prob_b = round(precision*temp)/precision;
    set(handles.warningB, 'String', strcat('Updated value of P(B|B):', num2str(prob_b)));
    set(handles.CondProbB, 'String', num2str(prob_b));
    set(handles.ProbBSlider, 'Value', prob_b);
end

% --- Executes during object creation, after setting all properties.
function CondProbB_CreateFcn(hObject, eventdata, handles)

global prob_b;

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

set(hObject, 'String', num2str(prob_b));

function StateInitial_Callback(hObject, eventdata, handles)

global prob_state precision;

temp_str = get(handles.StateInitial,'String');
temp = str2double(temp_str);

if (isempty(temp) || (temp < 0) || isnan(temp) || (temp > 1) || ~isreal(temp)) % the input is invalid
    set(handles.warningState, 'String', ...
    strcat('INVALID INPUT for StateInit:',temp_str, '. Current value: ',...
    num2str(prob_state)));
else
    prob_state = round(precision*temp)/precision;
    set(handles.warningState, 'String', strcat('Updated value of StateInit:', num2str(prob_state)));
    set(handles.StateInitial, 'String', num2str(prob_state));
    set(handles.StateSlider, 'Value', prob_state);
end

% --- Executes during object creation, after setting all properties.
function StateInitial_CreateFcn(hObject, eventdata, handles)

global prob_state;

if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

set(hObject, 'String', num2str(prob_state));

% --- Executes on button press in StartButton.
function StartButton_Callback(hObject, eventdata, handles)

disp('Markov Chain simulation started')
set(handles.warningA, 'String', ' ');
set(handles.warningB, 'String', ' ');
set(handles.warningState, 'String', ' ');

markov2f(handles.StateAxes);

function markov2f(hAxes);

global prob_a prob_b prob_state;

%To do a simple 2x2 Markov chain and plot the change in the state
x=zeros(1,25);
y=zeros(1,25);
x(1)=prob_state;
y(1)=1-x(1);
p=prob_a;
q=prob_b;
T=[p,1-q;1-p,q];

for n=1:24
    axes(hAxes);
    axis on;
    x(n+1)=T(1,1)*x(n)+T(1,2)*y(n);
    y(n+1)=T(2,1)*x(n)+T(2,2)*y(n);
    plot(hAxes, x(1:n));grid on;
    hold on
    plot(hAxes,y(1:n));
    axis([0,25,0,1]);
    drawnow;
end

hold off;
disp(x(25));