Logistic Regression vs Linear Regression: What’s the Difference?

Logistic Regression and Linear Regression are two of the most commonly used statistical methods in predictive analytics and data science. While both methods are used for regression analysis, there are some important differences between the two that are worth considering.

What is Logistic Regression?

Logistic Regression is a statistical method used for binary classification problems. It is used to model the relationship between a set of independent variables and a binary dependent variable, such as “yes” or “no.” The output of a logistic regression model is a probability score that predicts the likelihood of the dependent variable being “yes.”

What is Linear Regression?

Linear Regression, on the other hand, is a statistical method used for continuous regression problems. It is used to model the relationship between a set of independent variables and a continuous dependent variable, such as a numerical value or a date. The output of a linear regression model is a linear combination of the independent variables that predicts the value of the dependent variable.

Difference between Logistic Regression and Linear Regression

While both methods are used for regression analysis, there are some key differences between logistic regression and linear regression. One of the main differences is the type of dependent variable they are used to model. Logistic regression is used for binary classification problems, while linear regression is used for continuous regression problems.

Another difference between the two methods is the type of output they produce. Logistic regression produces a probability score that predicts the likelihood of the dependent variable being “yes,” while linear regression produces a linear combination of the independent variables that predicts the value of the dependent variable.

In addition, the assumptions and mathematical techniques used for each method are different. Logistic regression uses maximum likelihood estimation to estimate the coefficients of the model, while linear regression uses ordinary least squares.

Example Code

Here is an example code snippet in Python to implement logistic regression using the scikit-learn library:

``````import numpy as np
import pandas as pd
from sklearn.linear_model import LogisticRegression
from sklearn.model_selection import train_test_split
from sklearn.metrics import confusion_matrix, accuracy_score

# Split the data into training and testing sets
X_train, X_test, y_train, y_test = train_test_split(data.iloc[:, :-1], data.iloc[:, -1], test_size=0.2)

# Train the model
model = LogisticRegression()
model.fit(X_train, y_train)

# Predict the output
y_pred = model.predict(X_test)

# Evaluate the model
confusion_matrix = confusion_matrix(y_test, y_pred)
accuracy = accuracy_score(y_test, y_pred)

print("Confusion Matrix:")
print(confusion_matrix)
print("Accuracy:", accuracy)
``````

In conclusion, Logistic Regression and Linear Regression are two important statistical methods used in predictive analytics and data science. While both methods are used for regression analysis, they have some key differences, including the type of dependent variable they are used to model and the type of output they produce. By understanding these differences, you can choose the right method for your predictive analytics problem.