Make biplot using ggplot.

Principal Component Analysis (PCA) is a statistical procedure that uses an orthogonal transformation to convert a set of observations of possibly correlated variables into set of values of linearly un correlated variables. (from wiki) R can preform PCA very simple command “prcomp”. The result can visualise using biplot function. ggplot2 is a plotting system for

statistics in python

T-test uses a statistical examination of two population means. To perform t-test in python, scipy package is good tool to do that. For example I have data, that collected two times. 1st time [54.3, 55.2, 55.0, 56.4, 53.1, 53.1] 2nd time [56.5, 54.8, 58.2, 57.8, 59.0, 60.7] Is there the difference in means of two