Correlation coefficient and correlation test in R

Correlations between variables play an important role in a descriptive analysis. A correlation measures the relationship between two variables, that is, how they are linked to each other. In this sense, a correlation allows to know which variables evolve in the same direction, which ones evolve in the opposite direction, and which ones are independent.

In this tutorial, I show how to compute correlation coefficients, how to perform correlation tests and how to visualize relationships between variables in R.