导出r中的PCA组件

Question

我使用r对我的数据进行了pca，并且我试图保存特征值大于1的组件。

> summary(pca1)
Importance of components:
                          Comp.1    Comp.2    Comp.3    Comp.4    Comp.5     Comp.6     Comp.7     Comp.8
Standard deviation     1.2851803 1.1245020 1.0737268 1.0011978 0.9841687 0.88758402 0.84798807 0.67308490
Proportion of Variance 0.2064611 0.1580631 0.1441112 0.1252996 0.1210735 0.09847567 0.08988547 0.05663041
Cumulative Proportion  0.2064611 0.3645241 0.5086353 0.6339349 0.7550084 0.85348412 0.94336959 1.00000000
> loadings(pca1)

Loadings:
                            Comp.1 Comp.2 Comp.3 Comp.4 Comp.5 Comp.6 Comp.7 Comp.8
AspectRatio                  0.604         0.325                0.230  0.194  0.652
CPUSpeed                     0.241                0.278  0.890 -0.242              
IsDvrEnabled                 0.428        -0.329 -0.109 -0.290 -0.724 -0.281       
ZoomMode                     0.123         0.837        -0.133 -0.232 -0.124 -0.432
Tuner_BitRate                0.600        -0.272                0.392  0.161 -0.616
Tuner_Hole                                       -0.948  0.306                     
Receiver_VideoDecoderErrors        -0.705                       0.283 -0.640       
Receiver_AudioDecoderErrors -0.128 -0.690                      -0.275  0.650       

               Comp.1 Comp.2 Comp.3 Comp.4 Comp.5 Comp.6 Comp.7 Comp.8
SS loadings     1.000  1.000  1.000  1.000  1.000  1.000  1.000  1.000
Proportion Var  0.125  0.125  0.125  0.125  0.125  0.125  0.125  0.125
Cumulative Var  0.125  0.250  0.375  0.500  0.625  0.750  0.875  1.000

所以在这个例子中，我对前四个组件感兴趣。是否有办法将其保存在表或文件中(提供文件)。谢谢!

Answer 1

loadings(pca1)返回PCA负载。unclass删除类并将其转换为matrix。

pca1$sdev^2 > 1为特征值> 1的列返回TRUE。[...,drop = F]选择索引等于TRUE的列，同时保持矩阵结构，即使只选择一列。write.csv将结果写入文件。

最终代码：write.csv(x = unclass(loadings(pca1))[,(pca1$sdev^2 > 1),drop = FALSE], file = "filename.csv")