如何在matlab中绘制具有不同颜色和组的条形图

Question

我想绘制一个总结算法性能的条形图。它有三个主要参数

1. 出版年（x轴）
2. 数据类型（栏的颜色）
3. 算法评分（杆高度）

下面是一个例子的数据：

dtypes = {'type1','type2','type3'}; %All of the possible data types 
methods_name = {'method1','method2','method3'}; 
methods_accuracy = [89.2, 95.54, 85]; 
methods_year = [2016, 2017, 2016] ; 
methods_dtype = {'type1', 'type2', 'type2'}; 

在这里，我希望得到3个酒吧，其中2个在2016年用不同的颜色，一个在2017年有一个色彩匹配一个F rom 2016.

出于某种原因，我似乎无法使用bar函数来执行我想要的操作。这似乎很简单，但我认为我错过了这个功能的工作原理。 使用

bar(methods_year, methods_accuracy) 

给出了一个错误：

XData cannot contain duplicate values. 

Answer 1

绘制每个类别的多条似乎是通过使用矩阵常见的做。根据你的评论，这似乎不可能。似乎bar()函数也不能接受颜色矢量。下面的代码应该更通用一些，并允许你根据你的'类型'来指定条的颜色。

我修改了MATLAB Answers论坛（https://ch.mathworks.com/matlabcentral/answers/310039-how-to-change-the-color-of-individual-bars-in-a-bar-chart）上提供的代码以解释您的数据类型并将数据处理成正确的格式。

% code modified from https://ch.mathworks.com/matlabcentral/answers/310039-how-to-change-the-color-of-individual-bars-in-a-bar-chart 

% Plots a bar chart and gives a different color to each bar. 
% Also plots the value of the bar above the bar. 
clc; % Clear the command window. 
close all; % Close all figures (except those of imtool.) 
clear; % Erase all existing variables. 
workspace; % Make sure the workspace panel is showing. 
fontSize = 10; 
format compact 

%%%%%%%%%%%%%%%%%%%%% your data here %%%%%%%%%%%%%%%%%%%%%%%% 
dtypes = {'type1','type2','type3'}; %All of the possible data types 
methods_name = {'method1','method2','method3'}; 
methods_accuracy = [89.2, 95.54, 85]; 
methods_year = [2016, 2017, 2016] ; 
methods_dtype = {'type1', 'type2', 'type2'}; 

% sorting all vectors into values 
[sort_yrs,inds] = sort(methods_year); 
sort_methods = methods_name(inds); 
sort_dtype = methods_dtype(inds); 
sort_accuracy = methods_accuracy(inds); 
colors = zeros([length(sort_methods),3]); 
colors_types = [[1,0,0];[0,1,0];[0,0,1]]; 

for i = 1:1:length(dtypes) 
    ind1 = strfind(sort_dtype, dtypes{i}); 
    ind2 = find(not(cellfun('isempty', ind1))); 
    for j = 1:1:length(ind2) 
     colors(ind2(j),:) = colors_types(i,:); 
    end 
end 
%%%%%%%%%%% end of processing data %%%%%%%%%%%%%% 

% plotting all bars in a loop 
for b = 1 : length(sort_accuracy) 

    % plot a single bar 
    handlebar(b) = bar(b, sort_accuracy(b), 'BarWidth', 0.9); 

    % assigning color to bar 
    set(handlebar(b), 'FaceColor', colors(b,:)); 
    hold on; 
end 

% title and axis labels, if desired 
title('A title Here', 'FontSize', fontSize); 
xlabel('x', 'FontSize', fontSize); 
ylabel('y', 'FontSize', fontSize); 

% finding locations for tick labels for years, if desired 
temp = histc(sort_yrs,unique(sort_yrs)); 
% locations to use if at the middle of the year 
xTickLocs = cumsum(temp) - 0.5*temp; 
% locations to use if at the beginning of the year 
%xTickLocs = cumsum(temp) - 0.5*temp(1); 

xticks(xTickLocs); 
xticklabels(unique(sort_yrs)); 
% addind labels 
set(gca, 'XTickLabels', xticklabels);