When a correlation, usually Person type correlation, is calculated, two variables have to be continuous. But this requirement does not…
dplyr is a package that belongs to tidyverse framework. dplyr allows usage of pipeline structure (%>%), which can chain multiple…
R language provides several useful functions for importing delimited files and creating data frames. These delimited files are often stored…
Categorical variables, including nominal and ordinal variables in R programming language are called factor variables. For example, gender(male/female) is nominal,…
When R software and RStudio program have been installed on your computer, R working session can be simply started by…
list is a type of data structure in R programming language. Unlike other data structures, especially matrix and vector, in…
Violin plot is quite similar as boxplot, in the sense that it shows the range of the data. And at…
A Student t-distributed random variable is modeling the ratio between a standard Normal random variate and square root of a…
Kernel density function is a nonparametric method to find the drawing density curve of random samples, and it is often…
In hypothesis testing, the analyst has chance to commit both Type I and Type II errors. The Type I error…