digits: 1797 rows, 61 features
PC1  12.0% (cum.  12.0%)  pixel_0_2 -0.29, pixel_7_2 -0.28, pixel_1_1 -0.25
PC2   9.6% (cum.  21.6%)  pixel_0_5 +0.27, pixel_1_6 +0.27, pixel_6_6 -0.26
PC3   8.4% (cum.  30.0%)  pixel_5_3 -0.32, pixel_4_3 -0.28, pixel_5_4 -0.27
components for 80% of the variance: 21
components for 90% of the variance: 31
components for 95% of the variance: 40
