examplebutton_callback.m

流形学习程序

function ExampleButton_Callback(hObject, eventdata, handles)
% --- Executes on button press in ExampleButton.

exampleValue = get(handles.ExampleMenu,'Value');
N = round(str2double(get(handles.PointsEdit,'String')));   % Number of points to use.
N = max(1,N);
ExParam = str2double(get(handles.ParamEdit,'String'));  % Second parameter for example
ExParam = max(0.0,ExParam);
switch exampleValue
    case 1  % Swiss Roll
        tt = (3*pi/2)*(1+2*rand(1,N));  
        height = 21*rand(1,N);
        handles.X = [tt.*cos(tt); height; ExParam*tt.*sin(tt)]';
        handles.ColorVector = tt';
        updateString{1} = 'Swiss Roll example loaded.';
    case 2  % Swiss Hole
        % Swiss Roll w/ hole example taken from Donoho & Grimes
        tt = (3*pi/2)*(1+2*rand(1,2*N));  
        height = 21*rand(1,2*N);
        kl = repmat(0,1,2*N);
        for ii = 1:2*N
            if ( (tt(ii) > 9)&(tt(ii) < 12))
                if ((height(ii) > 9) & (height(ii) <14))
                    kl(ii) = 1;
                end;
            end;
        end;
        kkz = find(kl==0);
        tt = tt(kkz(1:N));
        height = height(kkz(1:N));
        handles.X = [tt.*cos(tt); height; ExParam*tt.*sin(tt)]';     
        handles.ColorVector = tt';
        updateString{1} = 'Swiss Hole example loaded.';
    case 3  % Corner Planes
        k = 1;
        xMax = floor(sqrt(N));
        yMax = ceil(N/xMax);
        cornerPoint = floor(yMax/2);
        for x = 0:xMax
            for y = 0:yMax
                if y <= cornerPoint
                    X(k,:) = [x,y,0];
                    ColorVector(k) = y;
                else
                    X(k,:) = [x,cornerPoint+(y-cornerPoint)*cos(pi*ExParam/180),(y-cornerPoint)*sin(pi*ExParam/180)];
                    ColorVector(k) = y;
                end;
                k = k+1;
            end;
        end;
        handles.X = X;
        handles.ColorVector = ColorVector';
        updateString{1} = 'Corner Planes example loaded.';
    case 4  % Punctured Sphere by Saul & Roweis
        inc = 9/sqrt(N);   %inc = 1/4;
        [xx,yy] = meshgrid(-5:inc:5);
        rr2 = xx(:).^2 + yy(:).^2;
        [tmp ii] = sort(rr2);
        Y = [xx(ii(1:N))'; yy(ii(1:N))'];
        a = 4./(4+sum(Y.^2));
        handles.X = [a.*Y(1,:); a.*Y(2,:); ExParam*2*(1-a)]';
        handles.ColorVector = handles.X(:,3);
        updateString{1} = 'Punctured Sphere example loaded.';
    case 5  % Twin Peaks by Saul & Roweis
        inc = 1.5 / sqrt(N);  % inc = 0.1;
        [xx2,yy2] = meshgrid(-1:inc:1);
        zz2 = sin(pi*xx2).*tanh(3*yy2);
        xy = 1-2*rand(2,N);
        handles.X = [xy; sin(pi*xy(1,:)).*tanh(3*xy(2,:))]';
        handles.X(:,3) = ExParam * handles.X(:,3);
        handles.ColorVector = handles.X(:,3);
        updateString{1} = 'Twin Peaks example loaded.';
    case 6  % 3D Clusters
        numClusters = ExParam;
        numClusters = max(1,numClusters);
        Centers = 10*rand(numClusters,3);
        D = L2_distance(Centers',Centers',1);
        minDistance = min(D(find(D>0)));
        k = 1;
        N2 = N - (numClusters-1)*9;
        for i = 1:numClusters
            for j = 1:ceil(N2/numClusters)
               X(k,1:3) = Centers(i,1:3)+(rand(1,3)-0.5)*minDistance/sqrt(12);
               ColorVector(k) = i;
               k = k + 1;
           end;
           % Connect clusters with straight line.
           if i < numClusters
               for t = 0.1:0.1:0.9
                    X(k,1:3) = Centers(i,1:3) + (Centers(i+1,1:3)-Centers(i,1:3))*t;
                    ColorVector(k) = 0;
                    k = k+1;
                end;
           end;
        end;
        handles.X = X;
        handles.ColorVector = ColorVector;
        updateString{1} = '3D Clusters example loaded.';
    case 7  % Toroidal Helix by Coifman & Lafon
        noiseSigma=0.05;   %noise parameter
        t = (1:N)'/N;
        t = t.^(ExParam)*2*pi;
        handles.X = [(2+cos(8*t)).*cos(t) (2+cos(8*t)).*sin(t) sin(8*t)]+noiseSigma*randn(N,3);
        handles.ColorVector = t;
        updateString{1} = 'Toroidal Helix example loaded.';
    case 8  % Gaussian randomly sampled
        X = ExParam * randn(N,3);
        X(:,3) = 1 / (ExParam^2 * 2 * pi) * exp ( (-X(:,1).^2 - X(:,2).^2) / (2*ExParam^2) );
        handles.X = X;
        handles.ColorVector = X(:,3);
        updateString{1} = 'Gaussian example loaded.';
    case 9  % Occluded disks
        m = 20;   % Image size m x m.
        Rd = 3;   % Disk radius.
        Center = (m+1)/2;
        u0 = zeros(m,m);
        for i = 1:m
            for j = 1:m
                if (Center - i)^2 + (Center - j)^2 < ExParam^2
                    u0(i,j) = 1;
                end;
            end;
        end;
        for diskNum = 1:N
            DiskX(diskNum) = (m-1)*rand+1;
            DiskY(diskNum) = (m-1)*rand+1;
            u = u0;
            for i = 1:m
                for j = 1:m
                    if (DiskY(diskNum) - i)^2 + (DiskX(diskNum) - j)^2 < Rd^2
                        u(i,j) = 1;
                    end;
                end;
            end;
            X(diskNum,:) = reshape(u,1,m*m);
        end;
        % Since this is a special manifold, plot separately.
        axes(handles.maniAXES);
        t = 0:0.1:2*pi+0.1;
        plot(ExParam*cos(t)+Center,ExParam*sin(t)+Center);
        axis([0.5 m+0.5 0.5 m+0.5]);
        hold on;
        handles.ColorVector = (sqrt((DiskX-Center).^2+(DiskY-Center).^2))';
        scatter(DiskX,DiskY,12,handles.ColorVector');
        hold off;
        handles.X = X;
        updateString{1} = 'Occluded Disks example loaded.';
        updateString{3} = 'Warning: Embedding may be slow.';
    case 10  % Swiss Roll
        tt = (rand(1,N)*3-2)*pi;  
        height = 5*rand(1,N);
        handles.X = [cos(tt); height; (sin(tt)-1).*sign(pi/2-tt)]';
        handles.ColorVector = tt';
        updateString{1} = 'Sigma example loaded.';
end;
assignin ('base','maniX',handles.X);
updateString{2} = 'Manifold data written to matrix "maniX"';
set(handles.UpdatesText,'String',updateString);
handles.isExample = 1;
guidata(hObject, handles);
if exampleValue ~= 9    % Already plotted Occluded Disks example.
    PlotManifold(hObject,eventdata,handles,0);
end;