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Matlab绘制柱状图（含显著性差异*）

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一、准备环境

matlab版本：matlab 2021b

代码使用之前必须先安装cbrewer函数包，参考链接： Matlab 绘图配色解决方案 — cbrewer 函数的介绍与使用

如果想添加显著性差异（*），必须下载sigline函数，参考链接： Statistical significance line

如存在问题，可在评论区留言，或者加作者微信：song408862610

二、柱状图绘制（看图，先睹为快）

1、不同条件的柱状图绘制

2、多组不同条件的柱状图绘制

3、多组不同条件的柱状图绘制（颜色由浅至深）

4、多组不同条件的柱状图绘制（不同组颜色不同，颜色由浅至深）

5、多组不同条件的柱状图绘制（添加显著性差异*）

三、柱状图绘制（matlab程序）

1、不同条件的柱状图绘制（code）

clear all; close all; clc;
%% n对应的是有几个柱子
data_mean = [212,238,250]; %均值
data_std = [56,65,59]; %标准差

%% 颜色选择 根据自己的需求选择
RGB1 = cbrewer('seq', 'Greys', 11, 'linear');
RGB2 = cbrewer('seq', 'Blues', 11, 'linear');
RGB3 = cbrewer('seq', 'Greens', 11, 'linear');
RGB = [RGB1(4,:);RGB2(5,:);RGB3(5,:)]; %每个柱子的颜色

%% 绘图
figure
y = data_mean; 
neg = data_std; 
pos = data_std; 
n = size(y,2);
x = 1 : n;
h = bar(x, y);
%% 单独设置第j个柱子的颜色
for j = 1 : n
    h.FaceColor = 'flat';
    h.CData(j,:) = RGB(j,:);
    h.EdgeColor = 'flat';
end
%% 获取误差线 x 值
xx = h.XEndPoints;
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
hold off
%% 设置figure的格式
% matlab中默认字体是 Arial 8 号
% 设置xticklabels和yticklabels的字体以及字体的大小
set(gca, 'FontSize',13);
set(gca,'FontName','Times New Roman');
% 设置 x 轴 xticklabels
set(gca, 'XTickLabel', {'\fontname{Times New Roman}Con1', '\fontname{Times New Roman}Con2', ...
    '\fontname{Times New Roman}Con3'},'FontSize',13);
% xticks([]) %如果不想设置xticklabels，使用该命令
% 设置 y 轴标签
ylabel('\fontname{Times New Roman}y\fontname{宋体}轴标签','FontSize',15);
% 设置y轴范围
ylim([0 350])
% 去除上边界和右边界
box off
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);

2、多组不同条件的柱状图绘制（code）

clear all; close all; clc;
%% 数据 % m * n的矩阵，m对应的是一共有几组，n对应的是每组有几个柱子
data_mean = [212,238,250;212,238,250];
data_std = [56,65,59;56,65,59];

%% 颜色选择 根据自己的需求选择
RGB1 = cbrewer('seq', 'Greys', 11, 'linear');
RGB2 = cbrewer('seq', 'Blues', 11, 'linear');
RGB3 = cbrewer('seq', 'Greens', 11, 'linear');
RGB = [RGB1(4,:);RGB2(5,:);RGB3(5,:)];
%% 绘图
figure
y = data_mean; 
neg = data_std; 
pos = data_std; 
m = size(y,1);
n = size(y,2);
x = 1 : m;
h = bar(x, y);
%% 单独设置第i个组第j个柱子的颜色
for i = 1 : m
    for j = 1 : n
        h(1, j).FaceColor = 'flat';
        h(1, j).CData(i,:) = RGB(j,:);
        h(1,j).EdgeColor = 'flat';
    end
end
%% 获取误差线 x 值
xx = zeros(m, n);
for i = 1 : n
    xx(:, i) = h(1, i).XEndPoints';
end
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
hold off
%% 设置figure的格式
% matlab中默认字体是 Arial 8 号
% 设置xticklabels和yticklabels的字体以及字体的大小
set(gca, 'FontSize',13);
set(gca,'FontName','Times New Roman');
% 设置 x 轴 xticklabels
set(gca, 'XTickLabel', {'\fontname{宋体}第\fontname{Times New Roman}1\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}2\fontname{宋体}组'},'FontSize',13);
% xticks([]) %如果不想设置xticklabels，使用该命令
% 设置legend图例
legend({'Con1', 'Con2', 'Con3'},'NumColumns',3,'Location','north','FontName','Times New Roman','FontSize',13);
legend('boxoff'); %去除legend的边框
% 设置 y 轴标签
ylabel('\fontname{Times New Roman}y\fontname{宋体}轴标签','FontSize',15);
% 设置y轴范围
ylim([0 400])
% 去除上边界和右边界
box off
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);

3、多组不同条件的柱状图绘制（颜色由浅至深）（code）

clear all; close all; clc;
%% 数据 % m * n的矩阵，m对应的是一共有几堆，n对应的是每堆有几个柱子
data_mean = [212,238,250;212,238,250;212,238,250;212,238,250];
data_std = [56,65,59;56,65,59;56,65,59;56,65,59];

%% 颜色选择 根据自己的需求选择
RGB1 = cbrewer('seq', 'Blues', 12, 'linear');
RGB2 = cbrewer('seq', 'Greens', 12, 'linear');
RGB3 = cbrewer('seq', 'Purples', 12, 'linear');
RGB1  = RGB1([5,7,8,9],:);
RGB2  = RGB2([5,7,8,9],:);
RGB3  = RGB3([5,7,8,9],:);
RGB = cat(3,RGB1,RGB2,RGB3);
%% 绘图
figure
y = data_mean; 
neg = data_std; 
pos = data_std; 
m = size(y,1);
n = size(y,2);
x = 1 : m;
h = bar(x, y);
%% 单独设置第i个组第j个柱子的颜色
for i = 1 : m
    for j = 1 : n
        h(1, j).FaceColor = 'flat';
        h(1, j).CData(i,:) = squeeze(RGB(i,:,j));
        h(1,j).EdgeColor = 'flat';
    end
end

%% 获取误差线 x 值
xx = zeros(m, n);
for i = 1 : n
    xx(:, i) = h(1, i).XEndPoints';
end
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
hold off
%% 设置figure的格式
% matlab中默认字体是 Arial 8 号
% 设置xticklabels和yticklabels的字体以及字体的大小
set(gca, 'FontSize',13);
set(gca,'FontName','Times New Roman');
% 设置 x 轴 xticklabels
set(gca, 'XTickLabel', {'\fontname{宋体}第\fontname{Times New Roman}1\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}2\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}3\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}4\fontname{宋体}组'}, 'FontSize',13);
% xticks([]) %如果不想设置xticklabels，使用该命令
% 设置legend图例
legend({'Con1', 'Con2', 'Con3'},'NumColumns',3,'Location','north','FontName','Times New Roman','FontSize',13);
legend('boxoff'); %去除legend的边框
% 设置 y 轴标签
ylabel('\fontname{Times New Roman}y\fontname{宋体}轴标签','FontSize',15);
% 设置y轴范围
ylim([0 400])
% 去除上边界和右边界
box off
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);

4、多组不同条件的柱状图绘制（不同组颜色不同，颜色由浅至深）（code）

clear all; close all; clc;
%% 数据 % m * n的矩阵，m对应的是一共有几堆，n对应的是每堆有几个柱子
data_mean = [212,238,250;212,238,250;212,238,250;212,238,250];
data_std = [56,65,59;56,65,59;56,65,59;56,65,59];

%% 颜色选择 根据自己的需求选择
RGB1 = cbrewer('seq', 'Blues', 12, 'linear');
RGB2 = cbrewer('seq', 'Greens', 12, 'linear');
RGB3 = cbrewer('seq', 'Purples', 12, 'linear');
RGB4 = cbrewer('seq', 'Greys', 12, 'linear');
RGB1  = RGB1([5,7,8,9],:);
RGB2  = RGB2([5,7,8,9],:);
RGB3  = RGB3([5,7,8,9],:);
RGB4  = RGB4([5,7,8,9],:);
RGB = cat(3,RGB1,RGB2,RGB3,RGB4);
%% 绘图
figure
y = data_mean; 
neg = data_std; 
pos = data_std; 
m = size(y,1);
n = size(y,2);
x = 1 : m;
h = bar(x, y);
%% 单独设置第i个组第j个柱子的颜色
for i = 1 : m
    for j = 1 : n
        h(1, j).FaceColor = 'flat';
        h(1, j).CData(i,:) = squeeze(RGB(j,:,i));
        h(1,j).EdgeColor = 'flat';
    end
end
%% 获取误差线 x 值
xx = zeros(m, n);
for i = 1 : n
    xx(:, i) = h(1, i).XEndPoints';
end
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
hold off
%% 设置figure的格式
% matlab中默认字体是 Arial 8 号
% 设置xticklabels和yticklabels的字体以及字体的大小
set(gca, 'FontSize',13);
set(gca,'FontName','Times New Roman');
% 设置 x 轴 xticklabels
set(gca, 'XTickLabel', {'\fontname{宋体}第\fontname{Times New Roman}1\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}2\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}3\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}4\fontname{宋体}组'}, 'FontSize',13);
% xticks([]) %如果不想设置xticklabels，使用该命令
% 设置legend图例
% 设置 y 轴标签
ylabel('\fontname{Times New Roman}y\fontname{宋体}轴标签','FontSize',15);
% 设置y轴范围
ylim([0 400])
% 去除上边界和右边界
box off
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);

5、多组不同条件的柱状图绘制（添加显著性差异*）（code）

clear all; close all; clc;
%% 数据 % m * n的矩阵，m对应的是一共有几组，n对应的是每堆有几个柱子
data_mean = [212,238,250;212,238,250]; % 均值
data_std = [56,65,59;56,65,59]; % 标准差

%% 颜色选择 根据自己的需求选择
RGB1 = cbrewer('seq', 'Greys', 11, 'linear');
RGB2 = cbrewer('seq', 'Blues', 11, 'linear');
RGB3 = cbrewer('seq', 'Greens', 11, 'linear');
RGB = [RGB1(4,:);RGB2(5,:);RGB3(5,:)];
%% 绘制bar图
figure
y = data_mean; 
neg = data_std; 
pos = data_std; 
m = size(y,1);
n = size(y,2);
x = 1 : m;
h = bar(x, y);
%% 单独设置第i个组第j个柱子的颜色
for i = 1 : m
    for j = 1 : n
        h(1, j).FaceColor = 'flat';
        h(1, j).CData(i,:) = RGB(j,:);
        h(1,j).EdgeColor = 'flat';
    end
end
%% 获取误差线 x 值
xx = zeros(m, n);
for i = 1 : n
    xx(:, i) = h(1, i).XEndPoints';
end
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
%% 绘制显著性差异
% 演示一下
t1 = 1; %第t1组
n1 = 1; %第t1组的第n1个柱子
n2 = 3; %第t1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],[],ySig);

% 再演示一下
t1 = 2; %第t1组
n1 = 2; %第t1组的第n1个柱子
n2 = 3; %第t1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],[],ySig);


%% 设置figure的格式
% matlab中默认字体是 Arial 8 号
% 设置xticklabels和yticklabels的字体以及字体的大小
set(gca, 'FontSize',13);
set(gca,'FontName','Times New Roman');
% 设置 x 轴 xticklabels
set(gca, 'XTickLabel', {'\fontname{宋体}第\fontname{Times New Roman}1\fontname{宋体}组', ...
    '\fontname{宋体}第\fontname{Times New Roman}2\fontname{宋体}组'},'FontSize',13);
% xticks([]) %如果不想设置xticklabels，使用该命令
% 设置legend图例
legend({'Con1', 'Con2', 'Con3'},'NumColumns',3,'Location','north','FontName','Times New Roman','FontSize',13);
legend('boxoff'); %去除legend的边框
% 设置 y 轴标签
ylabel('\fontname{Times New Roman}y\fontname{宋体}轴标签','FontSize',15);
% 设置y轴范围
ylim([0 450])
% 去除上边界和右边界
box off
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);

四、知乎大佬的代码

1、example1

clear; clc; close all;
% 数据 % m * n的矩阵，m对应的是一共有几组，n对应的是每堆有几个柱子
data_mean = [203, 218, 200, 292]; % 均值
data_std  = [56, 70, 59, 65]; % 标准差

% 颜色选择 根据自己的需求选择
RGB = [[1 0 0];
       [0 0 1];
       [0 1 0];
       [1 0 1]];
   
% 绘制bar图
figure;

y = data_mean; 
neg = data_std; 
pos = data_std; 
m = 1; 
n = size(y,2);
x = 1;
h = bar(x, y,0.4);


%% 单独设置第i个组第j个柱子的颜色
for i = 1 : m
    for j = 1 : n
        h(1, j).FaceColor = 'flat';
        h(1, j).CData(i,:) = RGB(j,:);
        h(1,j).EdgeColor = 'flat';
    end
end

%% 获取误差线 x 值
xx = zeros(m, n);
for i = 1 : n
    xx(:, i) = h(1, i).XEndPoints';
end
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
%% 绘制显著性差异
% 演示一下
t1 = 1; %第1组
n1 = 3; %第1组的第n1个柱子
n2 = 4; %第1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],ySig, 0.0001);

% 再演示一下
t1 = 1; %第1组
n1 = 2; %第1组的第n1个柱子
n2 = 4; %第1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],ySig+30, 0.007);
hold off;

xticks([]) %如果不想设置xticklabels，使用该命令
legend( {'因素A', '因素B', '因素C', '因素D'}, 'Location', 'northeast');
legend('boxoff'); %去除legend的边框
% 设置 y 轴标签
ylabel('时间(ms)');
% 设置x轴范围
xlim([0.6 1.55])
% 设置y轴范围
ylim([0 500])
% 去除上边界和右边界
box off
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);


function sigline(x, y, p)
hold on
x = x';

if p<0.001
    plot(mean(x),       y*1.15, '*k')          % the sig star sign
    plot(mean(x)- 0.02, y*1.15, '*k')          % the sig star sign
    plot(mean(x)+ 0.02, y*1.15, '*k')          % the sig star sign

elseif (0.001<=p)&&(p<0.01)
    plot(mean(x)- 0.01, y*1.15, '*k')         % the sig star sign
    plot(mean(x)+ 0.01, y*1.15, '*k')         % the sig star sign

elseif (0.01<=p)&&(p<0.05)
    plot(mean(x), y*1.15, '*k')               % the sig star sign
else
    print('not significance');
end

plot(x, [1;1]*y*1.1, '-k', 'LineWidth',1); % 显著性的那条直线
plot([1;1]*x(1), [y*1.05, y*1.1], '-k', 'LineWidth', 1); % 显著性的那条直线的左方下直线
plot([1;1]*x(2), [y*1.05, y*1.1], '-k', 'LineWidth', 1); % 显著性的那条直线的右方下直线

hold off
end

2、example2

clear all; close all; clc;
%% 数据 % m * n的矩阵，m对应的是一共有几组，n对应的是每堆有几个柱子
data_mean = [64,131.6;59.9,164.2;46.0,198.6;60,150]; % 均值
data_std = [8,7;8,8;7,8;8,7]; % 标准差

%% 颜色选择 根据自己的需求选择
RGB = [0.705882352941177,0.266666666666667,0.423529411764706;...
    0.231372549019608,0.490196078431373,0.717647058823529;...
    0.231372549019608,0.490196078431373,0.717647058823529];
%% 绘制bar图
figure
y = data_mean; 
neg = data_std; 
pos = data_std; 
m = size(y,1);
n = size(y,2);
x = 1 : m;
h = bar(x, y);
%% 单独设置第i个组第j个柱子的颜色
for i = 1 : m
    for j = 1 : n
        h(1, j).FaceColor = 'flat';
        h(1, j).CData(i,:) = RGB(j,:);
        h(1,j).EdgeColor = 'flat';
    end
end
%% 获取误差线 x 值
xx = zeros(m, n);
for i = 1 : n
    xx(:, i) = h(1, i).XEndPoints';
end
% 绘制误差线
hold on
errorbar(xx, y, neg, pos, 'LineStyle', 'none', 'Color', 'k', 'LineWidth', 1);
%% 绘制显著性差异
% 演示一下
t1 = 1; %第t1组
n1 = 1; %第t1组的第n1个柱子
n2 = 2; %第t1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
% sigline([x1,x2],[],ySig);
sigline([x1,x2],'p=0.05',ySig)
% 再演示一下
t1 = 2; %第t1组
n1 = 1; %第t1组的第n1个柱子
n2 = 2; %第t1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],'p=0.05',ySig);

% 再演示一下
t1 = 3; %第t1组
n1 = 1; %第t1组的第n1个柱子
n2 = 2; %第t1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],'p=0.05',ySig);

t1 = 4; %第t1组
n1 = 1; %第t1组的第n1个柱子
n2 = 2; %第t1组的第n2个柱子
%获取显著性差异线的x坐标
x1 = xx(t1,n1); x2 = xx(t1,n2);
%获取显著性差异线的y坐标
ySig = max(y(t1,n1)+pos(t1,n1),y(t1,n2)+pos(t1,n2));
%绘制显著性差异
sigline([x1,x2],'p=0.05',ySig);

%% 设置figure的格式
% matlab中默认字体是 Arial 8 号
% 设置xticklabels和yticklabels的字体以及字体的大小
set(gcf,'unit','centimeters','position',[5 5 15 10])
set(gca, 'FontSize',14);
set(gca,'FontName','Times New Roman');
% 设置 x 轴 xticklabels
set(gca, 'XTickLabel', {'\fontname{Times New Roman}A', ...
    '\fontname{Times New Roman}B',...
    '\fontname{Times New Roman}C',...
    '\fontname{Times New Roman}D'},'FontSize',14);
% xticks([]) %如果不想设置xticklabels，使用该命令
% 设置legend图例
legend({'legend1', 'legend2'},'NumColumns',2,'Location','northwest','FontName','Times New Roman','FontSize',14);
legend('boxoff'); %去除legend的边框
% 设置 y 轴标签
ylabel('\fontname{Times New Roman}{\it{J}}_2','FontSize',16);
% 设置y轴范围
% ylim([0 1.2])
% 去除上边界和右边界
box on
% 设置边框的粗细
set(gca,'XColor','k','YColor','k','linewidth',1);

五、可能存在的问题

1、sigline函数

function sigline(xs,lbl,h,yv)
%SIGLINE plots a line of statistical significance on the current axis
%   sigline(xs) plots a significance line between the value in the 2D
%   vector xs along the x-coordinate. 
% 
%   sigline(xs,lbl) places a text lbl beside the significance line.
% 
%   sigline(xs,lbl,h) attempts to plot the significance line above a
%   highest value in a graphics object with handle h. If h is not a
%   graphics handle, the line will be plotted above the value of h. 
% 
%   sigline(xs,...,vy) give a way to specify that the line be plotted above
%   vy which should not be assumed to be a graphics object. This is
%   optional and overrides h; but probaly won't ever be needed. The vy is a
%   value on the y-axis above which the sig line is plotted. It is only
%   useful for a possibly, rare occurance of a given y in h unwantedly
%   matching a graphic object in value.
% 
%   Examples #1: Plot 5 random points and add a significance line between
%   point 2 and 4.
%   plot(rand(5,1))
%   sigline([2,4])
% 
%   Examples #3: Plot 5 random points as bar chart and add a significance
%   line between point 2 and 3 and print p=0.05 beside it.
%   bar(rand(5,1))
%   sigline([2,3],'p=0.05')
% 
%   Examples #4: Plot 5 random points and add a significance line between
%   point 2 and 4 and specify the handle to be used to obtaine the value
%   above which the line will be plotted.
%   h=plot(rand(5,1))
%   sigline([2,4],[],h)
% 
%   Examples #5: Plot 5 random points and add a significance line between
%   point 2 and 4 and a value above which the line will be plotted.
%   plot(rand(5,1))
%   sigline([2,4],[],0.9)
%
%   TODO: To avoid messing up legend, we should redo this function using
%   drawing rather than plots? A work aroound for now is to plot legends b4
%   calling this function.

if nargin==1
    y=gety(gca);
    lbl=[];
elseif nargin==2
    y=gety(gca);
elseif nargin==3
    y=gety(h);
elseif nargin==4
    y=yv;
end


% Now plot the sig line on the current axis
hold on
xs=[xs(1);xs(2)];
plot(xs,[1;1]*y*1.1,'-k', 'LineWidth',1);%line
plot(mean(xs), y*1.15, '*k')% the sig star sign
if lbl
    text(mean(xs)*1.1, y*1.18, lbl)% the sig star sign
end
plot([1;1]*xs(1),[y*1.05,y*1.1],'-k', 'LineWidth',1);%left edge drop
plot([1;1]*xs(2),[y*1.05,y*1.1],'-k', 'LineWidth',1);%right edge drop
hold off

%--------------------------------------------------------------------------
% Helper function that Returns the largest single value of ydata in a given
% graphic handle. It returns the given value if it is not a graphics
% handle. 
function y=gety(h)
    %Returns the largest single value of ydata in a given graphic handle
    %h= figure,axes,line. Note that y=h if h is not a graphics
    if isgraphics(h) 
        switch(get(h,'type'))
            case {'line','hggroup','patch'},
                y=max(get(h,'ydata'));
                return;
            otherwise
                ys=[];
                hs=get(h,'children');
                for n=1:length(hs)
                    ys=[ys,gety(hs(n))];
                end
                y=max(ys(:));
        end
    else
        y=h;
    end
end

end