> set.seed(1)
> x  <- matrix(rnorm(200), nrow=20)
> p1 <- prcomp_irlba(x, n=3)
> summary(p1)
Importance of components%s:
                         PC1    PC2    PC3
Standard deviation     1.541 1.2513 1.1916
Proportion of Variance 0.443 0.2921 0.2649
Cumulative Proportion  0.443 0.7351 1.0000
> p2 <- prcomp(x, tol=0.7)
> summary(p2)
Importance of first k=3 (out of 10) components:
                          PC1    PC2    PC3
Standard deviation     1.5411 1.2513 1.1916
Proportion of Variance 0.2806 0.1850 0.1678
Cumulative Proportion  0.2806 0.4656 0.6334