Linear Regression in Machine Learning

Features of dataset:

Father - Height of father in inches.

Son - Height of son in inches.

Given the height of father we need to predict the height of son.  

Import required libraries

# For mathematical calculation

 import numpy as np

# For handling datasets import pandas as pd

# For plotting graphs 

from matplotlib import pyplot as plt 

# Import the sklearn library for linear regression 

from sklearn.linear_model import LinearRegression 

Import dataset

# Import the csv file df = pd.read_csv('data.csv' ,delim_whitespace=True) 

# prints the top 5 rows print df.head() ''' Output: Father Son 0 65.0 59.8 1 63.3 63.2 2 65.0 63.3 3 65.8 62.8 4 61.1 64.3 '''

Prepare data for training

# Prepare the training set x_train = df['Father'].values[:,np.newaxis] y_train = df['Son'].values

Train the model

lm = LinearRegression() 

# Train the model lm.fit(x_train, y_train)

Test the model

# Prepare the test data x_test = [[72.8],[61.1],[67.4],[70.2], [75.6],[60.2],[65.3],[59.2]] 

# Test the model predictions = lm.predict(x_test) print predictions ''' Output: [ 71.31243097 65.2985618 68.53679905 69.9760156 72.75164753 64.83595648 67.45738663 64.32195056] '''

Plot the best fit line

# Plot the training data plt.scatter(x_train, y_train,color='b') 

# Plot the best fit line using predicted value plt.plot(x_test, predictions,color='black' ,linewidth=3) plt.xlabel('Father height in inches') plt.ylabel('Son height in inches') plt.show()