To write a program to predict the profit of a city using the linear regression model with gradient descent.
- Hardware โ PCs
- Anaconda โ Python 3.7 Installation / Jupyter notebook
- Import pandas, numpy and mathplotlib.pyplot.
- Trace the best fit line and calculate the cost function.
- Calculate the gradient descent and plot the graph for it.
- Predict the profit for two population sizes.
Program to implement the linear regression using gradient descent.
Developed by: JANANI.S
RegisterNumber: 212222230049
import numpy as np
import pandas as pd
from sklearn.preprocessing import StandardScaler
def linear_regression(X1,y,learning_rate=0.01,num_iters=1000):
X=np.c_[np.ones(len(X1)),X1]
theta=np.zeros(X.shape[1]).reshape(-1,1)
for _ in range(num_iters):
predictions=(X).dot(theta).reshape(-1,1)
errors=(predictions-y).reshape(-1,1)
theta-=learning_rate*(1/len(X1))*X.T.dot(errors)
return theta
data=pd.read_csv('50_Startups.csv',header=None)
print(data.head())
X=(data.iloc[1:, :-2].values)
print(X)
X1=X.astype(float)
scaler=StandardScaler()
y=(data.iloc[1:,-1].values).reshape(-1,1)
print(y)
X1_Scaled=scaler.fit_transform(X1)
Y1_Scaled=scaler.fit_transform(y)
print(X1_Scaled)
print(Y1_Scaled)
theta=linear_regression(X1_Scaled,Y1_Scaled)
new_data=np.array([165349.2,136897.8,471784.1]).reshape(-1,1)
new_Scaled=scaler.fit_transform(new_data)
prediction=np.dot(np.append(1,new_Scaled),theta)
prediction=prediction.reshape(-1,1)
pre=scaler.inverse_transform(prediction)
print(f"Predicted value: {pre}")
Thus the program to implement the linear regression using gradient descent is written and verified using python programming.