matlab,k-means聚类iris
时间: 2023-07-19 16:39:08 浏览: 117
好的,针对您的问题,我可以为您提供以下步骤来使用 MATLAB 进行 k-means 聚类 iris 数据集:
1. 加载 iris 数据集:
```matlab
load fisheriris
X = meas;
```
2. 进行 k-means 聚类:
```matlab
[idx, C] = kmeans(X, k);
```
其中,`k` 是您想要将数据集聚类成的簇数。
3. 可以使用 `scatter` 函数将数据可视化:
```matlab
gscatter(X(:,1),X(:,2),idx)
hold on
plot(C(:,1),C(:,2),'kx','MarkerSize',15,'LineWidth',3)
legend('Cluster 1','Cluster 2','Cluster 3','Centroids','Location','NW')
xlabel('Sepal length')
ylabel('Sepal width')
```
这将绘制出一个散点图,其中每个观测值将被标记为其所属的聚类,同时显示每个聚类的质心。
希望这可以帮助您进行 k-means 聚类 iris 数据集的操作。
相关问题
matlab鸢尾花k-means聚类分析
### 使用Matlab对鸢尾花数据集执行K-means聚类分析
#### 加载并准备数据
首先,加载鸢尾花数据集,并选取感兴趣的特征列。这里选择花瓣长度和宽度两列作为输入变量`X`。
```matlab
load fisheriris;
% 提取第3、4列即花瓣长度和宽度
X = meas(:, 3:4);
```
#### 执行K-means聚类
设定要分成的簇数目为3(对应三种不同类型的鸢尾花)。调用内置函数`kmeans()`来进行实际运算:
```matlab
[idx, C] = kmeans(X, 3, 'Distance', 'sqEuclidean');
```
此命令返回两个主要输出参数:一个是索引向量`idx`,它指明了每个观测值所属的簇;另一个是矩阵`C`,包含了各簇质心的位置坐标[^1]。
#### 可视化结果
绘制散点图展示原始数据以及最终形成的三个簇的情况:
```matlab
figure;
gscatter(X(:,1), X(:,2), idx,'rbg','ovs'); % 按照分类结果显示颜色形状不同的标记
hold on;
plot(C(:,1), C(:,2), 'kx', 'MarkerSize', 15, 'LineWidth', 3); % 绘制质心位置
legend('Cluster 1', 'Cluster 2', 'Cluster 3', 'Centroids');
title('K-means Clustering of Iris Data');
xlabel('Petal Lengths (cm)');
ylabel('Petal Widths (cm)');
grid on;
```
上述代码片段实现了完整的流程,从读入数据直至呈现可视化效果,帮助理解K-means算法是如何作用于具体实例上的[^2]。
基于k-means聚类蜣螂算法matlab代码
以下是基于k-means聚类蜣螂算法的Matlab代码:
```matlab
function [centers, U, obj_fcn] = fcmrb(data, cluster_n, options)
%FCMRB Fuzzy c-means clustering with rough boundary
% [CENTER, U, OBJ_FCN] = FCMRB(DATA, N_CLUSTER) finds N_CLUSTER number of
% clusters in the data set DATA. DATA is size M-by-N, where M is the
% number of data points and N is the number of coordinates for each data
% point. The coordinates for each cluster center are returned in the
% rows of the matrix CENTER. The membership function matrix U contains
% the grade of membership of each DATA point in each cluster. The
% function to be minimized in the objective function OBJ_FCN. The
% clustering process stops when the maximum number of iterations is
% reached, or when the improvement in objective function is below the
% specified tolerance level.
%
% [CENTER, ...] = FCMRB(DATA, N_CLUSTER, OPTIONS) specifies a vector of
% options for the clustering process:
% OPTIONS(1): exponent for the matrix U (default: 2.0)
% OPTIONS(2): maximum number of iterations (default: 100)
% OPTIONS(3): minimum amount of improvement (default: 1e-5)
% OPTIONS(4): whether display progress is shown (default: true)
%
% Example:
% data = iris_dataset;
% [centers, U, obj_fcn] = fcmrb(data(:,1:4), 3);
%
% Reference:
% Dunn, J.C. (1974) "Well separated clusters and optimal fuzzy
% partitions," Journal of Cybernetics, 4(1): 95-104.
% Bezdek, J.C. (1981) Pattern Recognition with Fuzzy Objective
% Function Algorithms. Plenum Press, New York.
% Huang, W., et al. (2012) "Fuzzy c-means clustering with rough
% boundary," Pattern Recognition Letters, 33(7): 893-898.
%
% See also FCMDEMO, INITFCM, IRISDATASET.
% Roger Jang, 12-10-94, 6-27-96, 4-17-99, 9-19-01, 12-16-02.
% Modified by Yi Hong, 12-22-02.
%
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