# The relation of eigenvalue and PCs in PCA

In R, I got the result of PCA and eigenvalues and vectors and three eigenvalues above 1 were checked.

If so, is it valid data from PCA results to PC1 ~ 3?

Here is my eigen values and vectors,

eigen() decomposition
$values [1] 2.3502254 1.4170606 1.2658360 0.8148231 0.5608698 0.3438629 0.2473222$vectors
[,1]        [,2]        [,3]        [,4]        [,5]         [,6]         [,7]
[1,]  0.2388621  0.46839043  0.37003850  0.47205027 -0.58802244 -0.133939151 -0.009233395
[2,]  0.1671739 -0.71097984 -0.14062597  0.25083439 -0.26726985 -0.502411130 -0.244983436
[3,]  0.2132841 -0.19677142  0.64662974  0.34508779  0.61416969 -0.003950736  0.036814153
[4,]  0.1697817 -0.24468987  0.55631886 -0.69016805 -0.34039757  0.039899816  0.089531675
[5,]  0.4857016  0.36681570 -0.09905329 -0.31456085  0.26225761 -0.344919726 -0.577088755
[6,] -0.5359245  0.20164924  0.17958243 -0.13144417  0.11755661 -0.748885304  0.218966481
[7,]  0.5635252  0.03619081 -0.27131854 -0.05105919  0.08439733 -0.219629096  0.741315659


and, Here is my PCA result

Importance of components:
PC1    PC2    PC3    PC4     PC5     PC6     PC7
Standard deviation     1.5330 1.1904 1.1251 0.9027 0.74891 0.58640 0.49732
Proportion of Variance 0.3357 0.2024 0.1808 0.1164 0.08012 0.04912 0.03533
Cumulative Proportion  0.3357 0.5382 0.7190 0.8354 0.91554 0.96467 1.00000


but, in PC3 Cumulative Proportion is only 71.9%. Still, since the eigenvalue is 3, should I say that data only valid up to PC3?

for the comment, I added my scree plot.

## migrated from stackoverflow.comApr 24 at 7:52

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• What do you mean by the word "valid"? – jkpate Apr 24 at 9:46