Question

function res = plot2features(tset, f1, f2)
% Plots tset samples on a 2-dimensional diagram
%   using features f1 and f2
% tset - training set; the first column contains class label
% f1 - index of the first feature (mapped to horizontal axis)
% f2 - index of the second feature (mapped to vertical axis)
% 
% res - matrix containing values of f1 and f2 features

    % plotting parameters for different classes
    %   restriction to 8 classes seems reasonable
    pattern(1,:) = 'ks';
    pattern(2,:) = 'rd';
    pattern(3,:) = 'mv';
    pattern(4,:) = 'b^';
    pattern(5,:) = 'gs';
    pattern(6,:) = 'md';
    pattern(7,:) = 'mv';
    pattern(8,:) = 'g^';

    res = tset(:, [f1, f2]);

    % extraction of all unique labels used in tset
    labels = unique(tset(:,1));

    % create diagram and switch to content preserving mode
    figure;
    hold on;
    for i=1:size(labels,1)
        idx = tset(:,1) == labels(i);
        plot(res(idx,1), res(idx,2), pattern(i,:));
    end
    hold off;
end

我编写了这个函数，我想在MATLAB中的一个寡妇中显示多个plot2featutes()。

我尝试了以下内容，

subplot(2,2,1);plot2features(train, 2, 3);
subplot(2,2,2);plot2features(train, 2, 3);
subplot(2,2,3);plot2features(train, 2, 3);
subplot(2,2,4);plot2features(train, 2, 3);

那不起作用。

Answer 1

如评论中所述，问题在于您的函数中的行figure;。如果没有参数，figure会创建一个新的数字，然后将焦点切换到该数字。你的功能应该更像这样：

function res = plot2features(tset, f1, f2)
% Plots tset samples on a 2-dimensional diagram
%   using features f1 and f2
% tset - training set; the first column contains class label
% f1 - index of the first feature (mapped to horizontal axis)
% f2 - index of the second feature (mapped to vertical axis)
% 
% res - matrix containing values of f1 and f2 features

    % plotting parameters for different classes
    %   restriction to 8 classes seems reasonable
    pattern = {'ks'; 'rd'; 'mv'; 'b^'; 'gs'; 'md'; 'mv'; 'g^'};

    res = tset(:, [f1, f2]);

    % extraction of all unique labels used in tset
    labels = unique(tset(:,1));

    % create diagram and switch to content preserving mode
    for ii = 1:size(labels,1)
        if ii == 1
            hold off
        else
            hold on
        end
        idx = tset(:,1) == labels(ii);
        plot(res(idx,1), res(idx,2), pattern{ii});
    end
    hold off;
end

我对您的代码进行了三处更改：

我删除了figure并将其替换为在第一次传递时转为hold off的测试，以便创建一个新轴，然后在这些轴内绘制后续绘图。
我将您的索引从内置i（即sqrt（-1））更改为ii以避免歧义
我将pattern更改为一个单元格数组，除了我自己的个人美学外无其他理由。

这样打电话：

figure
subplot(2,2,1);plot2features(train, 2, 3);
subplot(2,2,2);plot2features(train, 2, 3);
subplot(2,2,3);plot2features(train, 2, 3);
subplot(2,2,4);plot2features(train, 2, 3);

如何在matlab中的一个窗口中显示多个图？

1 个答案: