## Principal Component Analysis (PCA) from Scratch

How to perform PCA step by step using R and basic linear algebra functions and operations. What is PCA? PCA is an exploratory data analysis based in dimensions reduction. The general idea is to reduce the dataset to have fewer dimensions and at the same time preserve as much information as possible. PCA allows us to make visual representations in two dimensions and check for groups or differences in the data related to different states, treatments, etc....