如何从 MATLAB 中的树状图中获取颜色？

Posted 2023-02-19

【中文标题】如何从 MATLAB 中的树状图中获取颜色？

【英文标题】：How to get colors from dendrogram in MATLAB?

【发布时间】：2021-07-09 14:28:21

【问题描述】：

我已经生成了一些示例数据的树状图，我想为我的观察结果分配颜色。

下面是如何将颜色从树状图匹配到观察结果的示例。

clear; close all; clc;

%% Generate example data
rng('default') % For reproducibility
N = 10; % number of observations
X = rand(N,3);

%% Get linkage
tree = linkage(X, 'average');

%% Get desired number of clusters
nClusters   = 2;
cutoff      = median([tree(end-nClusters+1,3) tree(end-nClusters+2, 3)]);

%% plot tree
figure
h = dendrogram(tree, 'ColorThreshold', cutoff); % h contains Line objects with the 'Color' property

【参考方案1】：

您需要在代码中添加以下内容：

%% get colors

linesColor = cell2mat(get(h,'Color')); % get lines color; 
colorList = unique(linesColor, 'rows');

% NOTE that each row is single line corresponding to the same row in tree
% variable. I use that property below.
X_color     = zeros(N,3);
X_cluster   = zeros(N,1);
for iLeaf = 1:N
    [iRow, ~] = find(tree==iLeaf);
    color = linesColor(iRow,:); % !
    
    % assign color to each observation
    X_color(iLeaf,:) = color; 
    % assign cluster number to each observation
    X_cluster(iLeaf,:) = find(ismember(colorList, color, 'rows')); 
end