NOTE: On April 2, 2018 I updated this video with a new video that goes, step-by-step, through PCA and how it is performed. Check it out!
https://youtu.be/FgakZw6K1QQ
RNA-seq results often contain a PCA or MDS plot. This StatQuest explains how these graphs are generated, how to interpret them, and how to determine if the plot is informative or not. I've got example code (in R) for how to do PCA and extract the most important information from it on the StatQuest GitHub: https://github.com/StatQuest/pca_demo/blob/master/pca_demo.R
For a complete index of all the StatQuest videos, check out:
https://statquest.org/video-index/
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0:00 Awesome song and introduction
1:45 An introduction to dimensions
6:29 Why we can omit dimensions
8:53 Principal components in terms of variance and covariance!!!
12:47 Transforming samples with loading scores
17:49 Review of main ideas
19:11 Scree plots for diagnostics
19:39 Loadings and Eignvectors
#statquest #PCA
