# How to extract correlation coefficient value from correlation test in R?

R ProgrammingServer Side ProgrammingProgramming

To perform the correlation test in R, we need to use cor.test function with two variables and it returns so many values such as test statistic value, degrees of freedom, the p-value, the confidence interval, and the correlation coefficient value. If we want to extract the correlation coefficient value from the correlation test output then estimate function could be used as shown in below examples.

## Example

Live Demo

x1<-rnorm(20,5,2)
y1<-rnorm(20,5,1)
cor.test(x1,y1)

## Output

Pearson's product-moment correlation
data: x1 and y1
t = -0.13423, df = 18, p-value = 0.8947
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
-0.4675990 0.4167308
sample estimates:
cor
-0.03162132

## Example

Live Demo

x3<-runif(50,2,5)
y3<-runif(50,2,10)
cor.test(x3,y3)

## Output

Pearson's product-moment correlation
data: x3 and y3
t = -0.80709, df = 48, p-value = 0.4236
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
-0.3817626 0.1680496
sample estimates:
cor
-0.1157106

## Example

Live Demo

x5<-rpois(100000,2)
y5<-rpois(100000,5)
cor.test(y5,y5)

## Output

Pearson's product-moment correlation
data: y5 and y5
t = 1.5006e+10, df = 99998, p-value < 2.2e-16
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
1 1
sample estimates:
cor
1

cor.test(y5,y5)\$estimate cor 1

Published on 10-Oct-2020 12:58:43