Data Science & Machine Learning
75.1K subscribers
815 photos
68 files
722 links
Join this channel to learn data science, artificial intelligence and machine learning with funny quizzes, interesting projects and amazing resources for free

For collaborations: @love_data
Download Telegram
🙏💸 500$ FOR THE FIRST 500 WHO JOIN THE CHANNEL! 🙏💸

Join our channel today for free! Tomorrow it will cost 500$!

https://t.me/+BMtJPVwqRjo3ZGVi

You can join at this link! 👆👇

https://t.me/+BMtJPVwqRjo3ZGVi
2
What are the new transformed features in PCA called?
Anonymous Quiz
11%
A) Clusters
73%
B) Principal Components
13%
C) Hyperplanes
3%
D) Labels
2🔥1
Which library module is commonly used for PCA in Python?
Anonymous Quiz
59%
A) sklearn.decomposition
25%
B) sklearn.cluster
8%
C) sklearn.tree
8%
D) numpy.random
4🤩1
𝗔𝗜/𝗠𝗟 𝗿𝗼𝗹𝗲𝘀 𝗮𝗿𝗲 𝗳𝗮𝘀𝘁𝗲𝘀𝘁-𝗴𝗿𝗼𝘄𝗶𝗻𝗴 𝗰𝗮𝗿𝗲𝗲𝗿 𝗳𝗶𝗲𝗹𝗱 𝗶𝗻 𝟮𝟬𝟮𝟲😍

The demand is real, salaries are high, and the talent gap is wide open

Enrol for AI/ML Certification Program by CCE, IIT Mandi!

Eligibility: Open to everyone
Duration: 6 Months
Program Mode: Online
Taught By: IIT Mandi Professors

Deadline :- 23rd May

𝗥𝗲𝗴𝗶𝘀𝘁𝗲𝗿 𝗡𝗼𝘄👇 :-

https://pdlink.in/4nmI024
.
🎓Get Placement Assistance With 5000+ Companies
1🤩1
Model Evaluation Metrics 📊🤖

👉 After building a Machine Learning model, we must check:
“How good is the model?”

This is done using evaluation metrics.

🔹 1. Why Model Evaluation is Important?
Measures model performance
Detects errors
Helps compare models
Prevents bad predictions

🔥 2. Evaluation Metrics for Regression
Used for predicting numbers

MAE (Mean Absolute Error)
👉 Average absolute error.

MAE = (1/n) Σ |y - ŷ|

Lower MAE = Better model

MSE (Mean Squared Error)
👉 Squares the errors.

MSE = (1/n) Σ (y - ŷ)^2

Punishes large errors more.

RMSE (Root Mean Squared Error)

RMSE = √MSE = √[(1/n) Σ (y - ŷ)^2]

Easy to interpret.

R² Score
Measures how well model explains data.

R² = 1 - [Σ(y - ŷ)^2 / Σ(y - ȳ)^2]
R² = 1 → Perfect model

Higher R² = Better performance
Where ŷ = predicted value, ȳ = mean of actual values

🔥 3. Evaluation Metrics for Classification
Used for categories

Accuracy

Accuracy = Correct Predictions / Total Predictions

Precision
👉 Out of predicted positives, how many are correct?

Precision = TP / (TP + FP)

Recall
👉 Out of actual positives, how many detected?

Recall = TP / (TP + FN)

F1-Score
Balance between precision & recall.

F1-Score = 2 (Precision × Recall) / (Precision + Recall)

🔹 4. Confusion Matrix
A table showing prediction results.

Actual Positive & Predicted Positive = TP (True Positive)
Actual Positive & Predicted Negative = FN (False Negative)
Actual Negative & Predicted Positive = FP (False Positive)
Actual Negative & Predicted Negative = TN (True Negative)

TP = model correctly predicted positive
TN = model correctly predicted negative
FP = model wrongly predicted positive
FN = model wrongly predicted negative

🔹 5. Implementation (Python)
from sklearn.metrics import accuracy_score

y_true = [0, 1, 1, 0]
y_pred = [0, 1, 0, 0]

print(accuracy_score(y_true, y_pred))


🔹 6. Why Metrics Matter?
Helps improve models
Used in interviews
Critical in real-world AI systems

🎯 Today’s Goal
Understand regression metrics
Learn classification metrics
Understand confusion matrix

💬 Tap ❤️ for more!
11👍2
Which metric is commonly used for classification problems?
Anonymous Quiz
21%
A) RMSE
23%
B) MAE
48%
C) Accuracy
7%
D) Variance
2
In a good regression model, the R² score should be:
Anonymous Quiz
24%
A) Close to 0
7%
B) Negative
67%
C) Close to 1
3%
D) Equal to 100
3👍1
Which metric balances Precision and Recall?
Anonymous Quiz
16%
A) Accuracy
11%
B) RMSE
71%
C) F1-Score
3%
D) MAE
3👏1
Overfitting vs Underfitting 🤖📉

👉 One of the most important concepts in Machine Learning.

A model should not:
Learn too little
Learn too much

It should learn just right

🔹 1. What is Underfitting?
👉 Underfitting happens when the model is too simple and cannot learn patterns properly.

Characteristics:
Poor performance on training data
Poor performance on testing data

Example
Trying to fit a straight line to highly complex data.

🔥 2. What is Overfitting?
👉 Overfitting happens when the model memorizes training data instead of learning general patterns.

Characteristics:
Very high training accuracy
Poor testing accuracy

Example
A student memorizes answers instead of understanding concepts.

🔹 3. Ideal Model (Best Case)
👉 Performs well on:
Training data
Testing data

This is called: Good Generalization

🔹 4. Visual Understanding
📉 Underfitting → Too simple
📈 Overfitting → Too complex
Balanced model → Best fit

🔹 5. Causes of Overfitting
Too much model complexity
Small dataset
Too many features

🔹 6. How to Reduce Overfitting
More training data
Feature selection
Cross-validation
Regularization
Simpler model

🔹 7. How to Reduce Underfitting
Use better features
Increase model complexity
Train longer

🔹 8. Why This is Important?
Critical interview topic
Improves model performance
Core ML concept

🎯 Today’s Goal
Understand overfitting
Understand underfitting
Learn solutions

💬 Tap ❤️ for more!
3