You can also use the Kaiser method to determine the number of components. As the computed principal component object contains the standard deviation of each component, we can compute the variance as the standard deviation, which is the square root the of variance. From the computed variance, we find both component 1 and 2 have a variance above 1.

Therefore, we can determine the number of principal components as 2 (both component 1 and 2). Also, we can draw a red line on the scree plot (as shown in the preceding figure) to indicate that we need to retain component 1 and 2 in this case.