MATLAB；带有 2+ / 拆分图例的饼图 R2017b

Question

我正在创建一个饼图，理想情况下希望图例水平显示在顶部和/或底部。然而，在几乎所有情况下，这是不可能的，因为传说已经脱离了数字。因此，理想情况下，我希望将图例分成两个（或更多）子图例并将它们单独放置。我知道这不是 MATLAB 中的内置功能（我使用的是 R2017b），但我不确定它是否可以工作？我见过一些人设法用折线图做类似的事情，但我无法让它们适应我的饼图。

示例代码：

% Set up a figure and make it a reasonable size/location.
figure( 1 )
set( gcf, 'Position', [ 350, 150, 750, 750 ] )

% Create a list of items for the food menu (example only).
Menu = { "Egg and Bacon", "Egg, Sausage and becon", "Egg and Spam", ...
         "Egg, bacon and Spam", "Egg, bacon, sausage and Spam",     ...
         "Spam, bacon, sausage and Spam", "Nothing"                    };

% Estimate the demand for said food items (example only).
Orders = randi( 150, 1, length( Menu ) );

% Make a pie chart showing what ratio the food was ordered.
Pie_Plot = pie( Orders );

% Create two ranges to grab the first and second half of the pie chart's 
% patches.
Range_1 =                  1 : 2 : ceil( length( Pie_Plot ) / 2 );
Range_2 = Range_1( end ) + 2 : 2 : length( Pie_Plot );

% In an ideal world this would be the first of two legends that would 
% display at the same time.
Ideal_Leg_Pt1 = legend( Pie_Plot( Range_1 ), ...
        Menu( round( Range_1 / 2 ) ), 'orientation', 'horizontal', ...
        'location', 'southoutside'                                    );

% A pause because the method doesn't work so without it, this legend 
% won't appear.                         
pause

% The second half of the ideal legend(s) solution; noting that when this 
% is created, the original
% legend is replaced.
Ideal_Leg_Pt2 = legend( Pie_Plot( Range_2 ), ...
        Menu( round( Range_2 / 2) ), 'orientation', 'horizontal', ...
        'location', 'northoutside'                                   );

% Pause for the same reasons as before.
pause

% This is what I'm currently stuck with; a legend that doesn't fit (I'm 
% aware I could make it vertical for example but this looks messy in my 
% eyes and I'm trying to avoid it unless there really is no way to make 
% the ideal method work).
Current_Leg = legend( Menu, 'orientation', 'horizontal', ...
        'location', 'northoutside'                          );

编辑：

这已被标记为可能重复，但我不认为它是（但是我可能是错的）。我已经查看了已链接到的解决方案，但它们主要是我在我的 OP 中提到的类似的东西，但我无法适应使用饼图。我可以接近（例如，zhqiat 的方法），但我不能让它完全适用于饼图。

在上述示例中，它的工作原理是绘制一些部分，创建一个新轴，然后绘制其余部分；但你不能用饼图做到这一点。我可以接近解决这个问题，但我最终得到了两个不能完美重叠的饼图。这就是为什么我不认为这是一个重复问题的核心；饼图似乎在本质上与常规图不同，许多似乎适用于常规线图的解决方案似乎不适用于饼图（但是，我坦率地承认，我可能只是忽略了一个简单的修改，它会使它们全部工作！ )。

上述示例的代码（在我的 OP 中直接放在 Ideal_Leg_Pt1 下，其他所有内容都在删除后）：

ax2 = axes('Position',get(gca,'Position'),...
           'Visible','off','Color','none');

Second_Pie = pie( Orders );

Ideal_Leg_Pt2 = legend( Second_Pie( Range_2 ), ...
        Menu( round( Range_2 / 2) ), 'orientation', 'horizontal', ...
        'location', 'northoutside' );

Answer 1

此方案要求≥R2018a

将水平图例分成多列/多行可能会达到您的目的，而不是使其复杂化。

legend(Menu, 'location', 'northoutside', 'orientation', 'horizontal', 'NumColumns', 3);

Answer 2

你说你有2018a（2017b）之前的Matlab版本，因此你不能申请@Sardar's answer。所以这是一种没有NumColumns 属性的方法：

我们从您的代码的第一部分开始（在与我的 2017a 兼容的版本中），您在其中创建饼图，并放置图例的前半部分：

figure(1);
set(gcf,'Position',[350,150,750,750])
% Create a list of items for the food menu (example only).
Menu = {'Egg and Bacon', 'Egg, Sausage and becon', 'Egg and Spam', ...
         'Egg, bacon and Spam', 'Egg, bacon, sausage and Spam',     ...
         'Spam, bacon, sausage and Spam', 'Nothing'};
% Estimate the demand for said food items (example only).
Orders = randi(150,1,length(Menu));
% Make a pie chart showing what ratio the food was ordered.
Pie_Plot = pie(Orders);
% Create two ranges to grab the first and second half of the pie chart's 
% patches.
Range_1 = 1:2:ceil(length(Pie_Plot)/2);
Range_2 = Range_1(end)+2:2:length(Pie_Plot);

% In an ideal world this would be the first of two legends that would 
% display at the same time:
Ideal_Leg_Pt1 = legend(Pie_Plot(Range_1),Menu(round(Range_1/2)),...
    'orientation', 'horizontal','EdgeColor','none');

接下来，我们将手动设置Ideal_Leg_Pt1 位置以获得一些空间：

Ideal_Leg_Pt1.Position(1:3) = [0 1-Ideal_Leg_Pt1.Position(4) 1];

现在我们用相同的饼图添加隐藏轴，但这次是图例的第二部分：

% the hidden axes are neded so the first legend won't be replaced:
hidden_ax = axes('Visible','off','NextPlot','add');
% we plot the same pie, only to create the objects in the legend:
Pie_Plot_2 = pie(Orders);
% The second half of the ideal legend(s) solution:
Ideal_Leg_Pt2 = legend(Pie_Plot_2(Range_2),Menu(round(Range_2/2)),...
    'orientation', 'horizontal','AutoUpdate','off',...
    'EdgeColor','none');

请注意，我们将Ideal_Leg_Pt2 的'AutoUpdate' property 设置为“关闭”，因此我们可以安全地删除虚拟饼图而无需从图例中删除项目：

% remove the extra dummy pie:
Pie_Plot_2.delete

现在我们可以设置Ideal_Leg_Pt2相对于Ideal_Leg_Pt1的位置，让它们看起来像一个图例：

% Define a position of the second legend to fit the first one:
% make the legend equally wide
Ideal_Leg_Pt2.Position([1 3]) = Ideal_Leg_Pt1.Position([1 3]);
% attach the two parts of the leggend
Ideal_Leg_Pt2.Position(2) = Ideal_Leg_Pt1.Position(2)-Ideal_Leg_Pt2.Position(4);

结果：

请注意，任何调整图形的大小都需要重新定位图例，因此如果这是一个问题，您可以设置图形的'SizeChangedFcn' 属性来为您执行此操作：

% updating the position of the legends upon resizing of the figure:
set(figure(1),'SizeChangedFcn',...
    ['Ideal_Leg_Pt1.Position(1:3) = [0 1-Ideal_Leg_Pt1.Position(4) 1];'...
     'Ideal_Leg_Pt2.Position([1 3]) = Ideal_Leg_Pt1.Position([1 3]);'...
     'Ideal_Leg_Pt2.Position(2) = Ideal_Leg_Pt1.Position(2)-Ideal_Leg_Pt2.Position(4);']);

或者设置一个小函数来做，保存在不同的M文件中：

function setLgePos(Ideal_Leg_Pt1,Ideal_Leg_Pt2)
Ideal_Leg_Pt1.Position(1:3) = [0 1-Ideal_Leg_Pt1.Position(4) 1];
Ideal_Leg_Pt2.Position([1 3]) = Ideal_Leg_Pt1.Position([1 3]);
Ideal_Leg_Pt2.Position(2) = Ideal_Leg_Pt1.Position(2)-Ideal_Leg_Pt2.Position(4);
end

并从图形属性中调用它：

set(figure(1),'SizeChangedFcn','setLgePos(Ideal_Leg_Pt1,Ideal_Leg_Pt2)');