如何为 MATLAB errorbar plot 的点和垂直线设置不同的图例？
How to set different legends for MATLAB errorbar plot's dot and vertical line?
我有一个显示均值和标准差的 errorbar 图。我希望有一个圆圈的图例项、均值和一个 separate 的条形图。像，
--------------------------
| o mean |
| | standard deviation |
--------------------------
MWE
errorbar([1 2], [2 3], [0.1 0.2], 'o');
legend('mean +- stddev', 'Location','north')
给我这个
一种方法是添加一条不可见的线。试试这个：
errorbar([1 2], [2 3], [0.1 0.2], 'o');
hold on;
plot(1,3,'-b');
legend('Mean','Standard deviation','Location','north');
这是在 的基础上添加的：
- 图例中表示误差线的线可以旋转，使其垂直，或保留其默认水平方向；
- 那条线的末端是 "closed" 和 短线 。
方法比较通用，支持：
- 任意 color、linestyle 和 markers 作为
errorbar 的参数。请注意，实际条形图始终绘制为没有标记的实线（使用指定的颜色）。这是根据 errorbar 行为。
- 新建的短线随图例移动。
- 那些行的宽度是一个可配置的参数。此外，errobar 的 length 是垂直情况下的参数。两者都根据图例以标准化单位定义。
该方法因 Matlab 版本而略有不同，因为 R2014b 中引入的图形 objects 发生了变化。此外，图例中的误差线可能是水平的或垂直的。
所以有四种情况。
案例 I：R2014b 之前的版本，图例中的水平误差线
绘制数据和图例后，代码遵循以下步骤：
- 获取图例的children
- 在children中找到合适的行
- 得到它的x和y坐标
- 利用这些坐标，在每一端创建两条短线。制作图例的那些线条 children，以便它们随之移动。
代码已在 Matlab R2010b 中测试。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .12; %// width of bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen) and create legend
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
h_le = legend('Mean','Standard deviation','Location','north');
%// Add short lines at each end of line in the legend
c_le = get(h_le, 'Children'); %// step 1
h_li = findobj(c_le, 'linestyle','-', 'color',color_spec, 'marker','none'); %// step 2
h_li = h_li(1); %// in case there's more than one
li_x = get(h_li,'XData'); %// step 3
li_y = get(h_li,'YData');
line(li_x([1 1]), li_y+wid*[-.5 .5], 'parent',h_le, 'color',color_spec); %// step 4
line(li_x([2 2]), li_y+wid*[-.5 .5], 'parent',h_le, 'color',color_spec);
案例二：R2014b，图例中的水平误差线
在 Matlab R2014b 中，图例不再是轴 object，也没有 children。所以第 1 步和第 2 步必须针对案例 I 进行修改：
- 创建图例时获取图例图标
- 在这些图标中找到合适的行
- 获取它的 x 和 y 坐标
- 利用这些坐标，在每一端创建两条短线。使这些线与初始线共享 parent，以便它们与图例一起移动。
此外，此 Matlab 版本中的新语法有助于稍微简化代码。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .12; %// width of bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen)
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
%// Create legend and add short lines at each end of line in the legend
[~, icons] = legend('Mean','Standard deviation','Location','north'); %// 1
li = findobj(icons, 'type','line', 'linestyle','-'); %// 2
li = li(1); %// in case there's more than one
li_x = li.XData; %// 3
li_y = li.YData;
line(li_x([1 1]), li_y+wid*[-.5 .5], 'parent',li.Parent, 'color',color_spec); %// 4
line(li_x([2 2]), li_y+wid*[-.5 .5], 'parent',li.Parent, 'color',color_spec);
案例 III：R2014b 之前的版本，图例中的垂直误差线
这与情况 I 类似，但需要对线的 x 和 y 坐标进行一些调整。此外，还引入了一个新参数来控制图例中误差条的长度。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .04; %// width of bar in legend. Normalized units
len = .45; %// length of main bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen) and create legend
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
h_le = legend('Mean','Standard deviation','Location','north');
%// Add short lines at each end of line in the legend
c_le = get(h_le, 'Children');
h_li = findobj(c_le, 'linestyle','-', 'color',color_spec, 'marker','none');
h_li = h_li(1); %// in case there's more than one
set(h_li,'XData', repmat(mean(get(h_li,'XData')),1,2));
set(h_li,'YData', mean(get(h_li,'YData'))+len*[-.5 .5]);
li_x = get(h_li,'XData');
li_y = get(h_li,'YData');
line(li_x+wid*[-.5 .5], li_y([1 1]), 'parent',h_le, 'color',color_spec);
line(li_x+wid*[-.5 .5], li_y([2 2]), 'parent',h_le, 'color',color_spec);
案例 IV：R2014b，图例中的垂直误差线
同样，这与案例 II 类似，但对线条的坐标进行了一些调整。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .05; %// width of small bars in legend. Normalized units
len = .45; %// length of main bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen)
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
%// Create legend, modify line and add short lines
[~, icons] = legend('Mean','Standard deviation','Location','north');
li = findobj(icons, 'type','line', 'linestyle','-');
li = li(1); %// in case there's more than one
li.XData = repmat(mean(li.XData),1,2);
li.YData = mean(li.YData)+len*[-.5 .5];
li_x = li.XData;
li_y = li.YData;
line(li_x+wid*[-.5 .5], li_y([1 1]), 'parent',li.Parent, 'color',color_spec);
line(li_x+wid*[-.5 .5], li_y([2 2]), 'parent',li.Parent, 'color',color_spec);
我有一个显示均值和标准差的 errorbar 图。我希望有一个圆圈的图例项、均值和一个 separate 的条形图。像，
--------------------------
| o mean |
| | standard deviation |
--------------------------
MWE
errorbar([1 2], [2 3], [0.1 0.2], 'o');
legend('mean +- stddev', 'Location','north')
给我这个
一种方法是添加一条不可见的线。试试这个：
errorbar([1 2], [2 3], [0.1 0.2], 'o');
hold on;
plot(1,3,'-b');
legend('Mean','Standard deviation','Location','north');
这是在
- 图例中表示误差线的线可以旋转，使其垂直，或保留其默认水平方向；
- 那条线的末端是 "closed" 和 短线 。
方法比较通用，支持：
- 任意 color、linestyle 和 markers 作为
errorbar的参数。请注意，实际条形图始终绘制为没有标记的实线（使用指定的颜色）。这是根据errorbar行为。 - 新建的短线随图例移动。
- 那些行的宽度是一个可配置的参数。此外，errobar 的 length 是垂直情况下的参数。两者都根据图例以标准化单位定义。
该方法因 Matlab 版本而略有不同，因为 R2014b 中引入的图形 objects 发生了变化。此外，图例中的误差线可能是水平的或垂直的。 所以有四种情况。
案例 I：R2014b 之前的版本，图例中的水平误差线
绘制数据和图例后，代码遵循以下步骤：
- 获取图例的children
- 在children中找到合适的行
- 得到它的x和y坐标
- 利用这些坐标，在每一端创建两条短线。制作图例的那些线条 children，以便它们随之移动。
代码已在 Matlab R2010b 中测试。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .12; %// width of bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen) and create legend
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
h_le = legend('Mean','Standard deviation','Location','north');
%// Add short lines at each end of line in the legend
c_le = get(h_le, 'Children'); %// step 1
h_li = findobj(c_le, 'linestyle','-', 'color',color_spec, 'marker','none'); %// step 2
h_li = h_li(1); %// in case there's more than one
li_x = get(h_li,'XData'); %// step 3
li_y = get(h_li,'YData');
line(li_x([1 1]), li_y+wid*[-.5 .5], 'parent',h_le, 'color',color_spec); %// step 4
line(li_x([2 2]), li_y+wid*[-.5 .5], 'parent',h_le, 'color',color_spec);
案例二：R2014b，图例中的水平误差线
在 Matlab R2014b 中，图例不再是轴 object，也没有 children。所以第 1 步和第 2 步必须针对案例 I 进行修改：
- 创建图例时获取图例图标
- 在这些图标中找到合适的行
- 获取它的 x 和 y 坐标
- 利用这些坐标，在每一端创建两条短线。使这些线与初始线共享 parent，以便它们与图例一起移动。
此外，此 Matlab 版本中的新语法有助于稍微简化代码。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .12; %// width of bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen)
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
%// Create legend and add short lines at each end of line in the legend
[~, icons] = legend('Mean','Standard deviation','Location','north'); %// 1
li = findobj(icons, 'type','line', 'linestyle','-'); %// 2
li = li(1); %// in case there's more than one
li_x = li.XData; %// 3
li_y = li.YData;
line(li_x([1 1]), li_y+wid*[-.5 .5], 'parent',li.Parent, 'color',color_spec); %// 4
line(li_x([2 2]), li_y+wid*[-.5 .5], 'parent',li.Parent, 'color',color_spec);
案例 III：R2014b 之前的版本，图例中的垂直误差线
这与情况 I 类似，但需要对线的 x 和 y 坐标进行一些调整。此外，还引入了一个新参数来控制图例中误差条的长度。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .04; %// width of bar in legend. Normalized units
len = .45; %// length of main bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen) and create legend
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
h_le = legend('Mean','Standard deviation','Location','north');
%// Add short lines at each end of line in the legend
c_le = get(h_le, 'Children');
h_li = findobj(c_le, 'linestyle','-', 'color',color_spec, 'marker','none');
h_li = h_li(1); %// in case there's more than one
set(h_li,'XData', repmat(mean(get(h_li,'XData')),1,2));
set(h_li,'YData', mean(get(h_li,'YData'))+len*[-.5 .5]);
li_x = get(h_li,'XData');
li_y = get(h_li,'YData');
line(li_x+wid*[-.5 .5], li_y([1 1]), 'parent',h_le, 'color',color_spec);
line(li_x+wid*[-.5 .5], li_y([2 2]), 'parent',h_le, 'color',color_spec);
案例 IV：R2014b，图例中的垂直误差线
同样，这与案例 II 类似，但对线条的坐标进行了一些调整。
%// Define graph aspect
color_spec = 'r'; %// color of data and bars.
linestyle_spec = '--'; %// linestyle for data. The bars are always solid
marker_spec = 'o'; %// marker for data
wid = .05; %// width of small bars in legend. Normalized units
len = .45; %// length of main bar in legend. Normalized units
%// Plot errobar
h_er = errorbar([1 2], [2 3], [0.1 0.2], [color_spec linestyle_spec marker_spec]);
%// Add dummy line for legend (as per Jens Boldsen)
hold on;
plot(0,0,color_spec); %// linestyle is always solid with no marker
%// Create legend, modify line and add short lines
[~, icons] = legend('Mean','Standard deviation','Location','north');
li = findobj(icons, 'type','line', 'linestyle','-');
li = li(1); %// in case there's more than one
li.XData = repmat(mean(li.XData),1,2);
li.YData = mean(li.YData)+len*[-.5 .5];
li_x = li.XData;
li_y = li.YData;
line(li_x+wid*[-.5 .5], li_y([1 1]), 'parent',li.Parent, 'color',color_spec);
line(li_x+wid*[-.5 .5], li_y([2 2]), 'parent',li.Parent, 'color',color_spec);