# How to Find the Correlation Coefficient in Python

09/16/2021

Contents

In this article, you will learn how to find the correlation coefficient in Python.

## Find the correlation coefficient

There are several ways to find the correlation coefficient in Python. Here are two common methods:

### Using the numpy library

```
import numpy as np
# create two arrays
x = np.array([1, 2, 3, 4, 5])
y = np.array([5, 7, 9, 11, 13])
# calculate the correlation coefficient
corr_coef = np.corrcoef(x, y)[0, 1]
print("Correlation coefficient:", corr_coef)
# Output:
# Correlation coefficient: 1.0
```

The corrcoef function from the numpy library returns the correlation coefficient matrix for the given arrays. We use [0, 1] to extract the correlation coefficient between the two arrays.

### Using the pandas library

```
import pandas as pd
# create a dataframe
df = pd.DataFrame({'x': [1, 2, 3, 4, 5], 'y': [5, 7, 9, 11, 13]})
# calculate the correlation coefficient
corr_coef = df['x'].corr(df['y'])
print("Correlation coefficient:", corr_coef)
# Output:
# Correlation coefficient: 1.0
```

The corr method from the pandas library calculates the pairwise correlation of columns in a dataframe. We select the correlation coefficient between columns ‘x’ and ‘y’ using the syntax df[‘x’].corr(df[‘y’]).