# How to get correlation matrix for a set of variables in R

Correlation coefficient between 2 variables ( or any number of variables ) can be found using the cor function.

For example, if you want to find out the correlation coefficient between the sepal’s length and width of the iris data set, use

> cor(iris[1:2],) Sepal.Length Sepal.Width Sepal.Length 1.0000000 -0.1175698 Sepal.Width -0.1175698 1.0000000

You can use the cor () function to find out the correlation matrix ( a matrix of correlation coefficients ) across all the variables in the iris data set as well.

> cor(iris[1:4]) Sepal.Length Sepal.Width Petal.Length Petal.Width Sepal.Length 1.0000000 -0.1175698 0.8717538 0.8179411 Sepal.Width -0.1175698 1.0000000 -0.4284401 -0.3661259 Petal.Length 0.8717538 -0.4284401 1.0000000 0.9628654 Petal.Width 0.8179411 -0.3661259 0.9628654 1.0000000