多轴绘图，但只有一个图例 [英] Plot with multiple axes but only one legend

问题描述

以下代码生成了一条绘图，其中有两条线分别指向左y轴，一条线指向右y轴.这两个地块都有自己的图例，但我只想列出所有3条线的图例.我也尝试将'y1'，'y2'字符串也放入第二个legend-命令，但这并没有解决.

The following code produces a plot with two lines reffering to the left y-axis and one line referring to the right y-axis. Both plots have their own legend, but I want only one legend listing all 3 lines. I tried to just put the 'y1','y2' strings into the 2nd legend-command as well, but that didn't work out.

line(x,y1,'b','LineWidth',2)

line(x,y2,'Color',[0,0.6,0.5],'LineWidth',2)

legend('y1','y2');

ax1 = gca;
ax2 = axes('Position',ax1.Position,'YAxisLocation','right', 'Color','none','YColor',[255,127,80]/256);
linkaxes([ax1,ax2],'x');

line(x,y3,'Parent',ax2,'LineWidth',2,'Color',[255,127,80]/256)

legend('y3')

推荐答案

这是一个棘手的问题，因为图例以某种方式连接到了轴上.由于将创建2个轴，因此将有2个图例.但是，有一个技巧可以实现您想要的.首先，在同一轴上绘制所有线，然后运行legend.然后创建第二根轴，然后将第三条线移动到第二根轴.因此，您的代码应如下所示:

This is a tricky problem since the legend are somehow connected to the axes. Since you will be creating 2 axes, hence there will be 2 legends. However there is a trick to achieve what you want. Firstly, plot all line on the same axes, then run legend. Then create 2nd axes and then move the third line to the 2nd axes. So your code should look like this:

% line
line(x,y1,'b','LineWidth',2)
line(x,y2,'Color',[0,0.6,0.5],'LineWidth',2)
l3=line(x,y3,'LineWidth',2,'Color',[255,127,80]/256)

% legend
legend('y1','y2','y3');

% 2nd axes
ax1 = gca;
ax2 = axes('Position',ax1.Position,'YAxisLocation','right', 'Color','none','YColor',[255,127,80]/256);
linkaxes([ax1,ax2],'x');

% move l3 to 2nd axes
set(l3,'Parent',ax2);

如果要使用'DisplayName'，则意味着它可以与line

If you want to use 'DisplayName', it meant to be used with line

line(x,y1,'Color','b','LineWidth',2,'DisplayName','y1');
line(x,y2,'Color',[0,0.6,0.5],'LineWidth',2,'DisplayName','y2');

legend('show');

这篇关于多轴绘图，但只有一个图例的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！