Linear Regression - Part 1

y = m * x + c

Source: https://en.wikipedia.org/wiki/Linear_regression

Imports



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import numpy as np
import matplotlib.pyplot as plt
from sklearn import linear_model

%matplotlib inline

Data



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data_points = 100
X = np.arange(-20, data_points - 20).reshape(-1,1) # one columns and many rows
m = np.random.rand() * 10
c = np.random.rand() * 10
Y = m * X + c + np.random.rand() * 5



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X[:5]



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Y[:5]

Modelling



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regr = linear_model.LinearRegression()
regr.fit(X, Y)

Evaluation



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from sklearn.metrics.regression import mean_squared_error

mean_squared_error(Y, regr.predict(X))



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print('Predicted Linear Regression Coefficient:', regr.coef_, '\t Actual Value:', m)
print('Predicted Linear Regression X-Intercept:', regr.intercept_, '\t Actual Value:', c)

Visualisation



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plt.figure(figsize=(15, 5))
plt.plot(X, Y, color='b', alpha=0.4)
plt.plot(X, regr.predict(X) + 5, color='r', alpha=0.4)
plt.legend(['Actual Line', 'Predicted Line + 5 offset'])
plt.xlabel('X - Input values')
plt.ylabel('Y - Response values')