What does the summary of PCA signifies

pca

#1

I am working on PCA I have find the of my problem and I have used summary function on it but I am not able to understand it.

summary(my.prc)

Importance of components:

                          PC1    PC2     PC3     PC4       PC5
Standard deviation     2.1824 1.3454 0.59393 0.27276 1.406e-16
Proportion of Variance 0.6804 0.2586 0.05039 0.01063 0.000e+00
Cumulative Proportion  0.6804 0.9390 0.98937 1.00000 1.000e+00

I am not able to understand what Proportion of variance and Cumulative Proportion


#2

Hello @hinduja1234.

Proportion of variance tells what proportion of variance in the data is explained by the PC .So PCA1 explains about 68% of the variability in data.
Cumulative on the other hand tells what proportion of variance is explained by PCA1+PCA2…
So PCA1+PCA2 together explain about 94% of variance whereas PCA1-3 explain about 99% of the variation in data.
Hope this helps!!