Giannis Tolios’ Post

Day 43 of #100DaysOfDataScience 📊 Built Student Performance Analysis using K-Means Clustering 🎓 ✔️ Data preprocessing & feature selection ✔️ Feature scaling ✔️ Applied K-Means clustering ✔️ Identified clusters: Struggling, Average & Top Performers ✔️ Cluster analysis & insights #DataScience #MachineLearning #Python #KMeans #AI GitHub : https://lnkd.in/dBG3wGAE

The Statistics Globe Hub is moving forward quickly and is about to enter its third month, with new content released each week. Access to the April modules is only available to those who join this month. If you are interested in these modules, you have seven days left to register until April 30. If you sign up by April 30, you will receive immediate access to all modules released in April. After April 30, these modules will no longer be available to new members. The April modules include: 🔹 Draw Synthetic Datasets with drawdata in Python 🔹 Monte Carlo Simulation 🔹 AI-Assisted Coding with gander in R 🔹 Animated Visualization with magick in R #Statistics #DataScience #AI #RStats #Python #MachineLearning #DataVisualization #StatisticsGlobeHub

Excited to share my latest project: LinearRegression-ML This is a beginner-friendly Machine Learning project focused on understanding and implementing Linear Regression from scratch. It includes practical notebooks like profit analysis and medical data predictions, along with clear explanations of loss and cost functions. ???What I learned =>Fundamentals of Linear Regression =>Cost & loss function implementation =>Real-world dataset analysis using Python #https://lnkd.in/guCQQdNe #MachineLearning #Python_Jupyter_Notebook #DataScience

Stop scrolling if you’ve ever wondered how people actually predict the future with data. I’ve been learning ARIMA forecasting recently, and I mapped out a simple roadmap that made everything click for me. It starts with getting comfortable in Python - Pandas for wrangling, Matplotlib for visualising. Then you move into the core ideas: stationarity, ACF, PACF, and how they shape the model. After that, it’s about building the ARIMA model, validating it properly, and using it to make real‑world predictions. What I enjoy most is how it turns raw, messy data into insights you can genuinely act on. Still learning, but enjoying the process 🚀 #DataScience #TimeSeries #ARIMA #Python #LearningJourney

Today, I focused on working with NumPy arrays. Building a solid foundation for data manipulation and analysis. Here’s what I practiced: 🔹 Created a 1D array with values from 1 to 15 🔹 Built a 2D array (3×4) filled with ones 🔹 Generated a 3×3 identity matrix 🔹 Explored key array properties like shape, type, and dimensions 🔹 Converted a regular Python list into a NumPy array This session helped me better understand how data is structured and handled in numerical computing. Getting comfortable with arrays is definitely a crucial step toward more advanced data analysis and machine learning tasks. Looking forward to building on this momentum 💡 #AI #MachineLearning #Python #NumPy #DataAnalysis #M4ACE

The Statistics Globe Hub is moving forward quickly and is about to enter its third month, with new content released each week. Access to the April modules is only available to those who join this month. If you are interested in these modules, you have seven days left to register until April 30. If you sign up by April 30, you will receive immediate access to all modules released in April. After April 30, these modules will no longer be available to new members. The April modules include: 🔹 Draw Synthetic Datasets with drawdata in Python 🔹 Monte Carlo Simulation 🔹 AI-Assisted Coding with gander in R 🔹 Animated Visualization with magick in R The visualization below shows some of the topics and graphs covered this month. More information about the Statistics Globe Hub: https://lnkd.in/e5YB7k4d #Statistics #DataScience #AI #RStats #Python #MachineLearning #DataVisualization #StatisticsGlobeHub

Days 68-69 of the #three90challenge 📊 Today I explored NumPy operations — specifically indexing and slicing arrays. After understanding NumPy basics, this step made it easier to access and manipulate data efficiently. What I practiced today: • Accessing elements using indexing • Extracting subsets of data using slicing • Working with multi-dimensional arrays • Performing operations on selected data Example thinking: Instead of looping through data manually, I can directly select and operate on specific parts of an array. Example: import numpy as np arr = np.array([10, 20, 30, 40, 50]) print(arr[1:4]) # Output: [20 30 40] This makes data manipulation faster and more intuitive. From handling data → to controlling it efficiently 🚀 GeeksforGeeks #three90challenge #commitwithgfg #Python #NumPy #DataAnalytics #LearningInPublic #Consistency #Upskilling

Day 72. Spent time going deeper into XGBoost today. Covered classification and worked through the math: gradients & hessian leaf weights similarity score & gain Some questions I tried to answer while learning: Why do we need Taylor expansion here? Why can’t we directly differentiate the objective? What makes decision trees non-smooth / non-differentiable? The key realization: since trees produce piecewise constant outputs, the loss surface isn’t smooth — which is why second-order approximation becomes necessary. Still revising, but things are starting to connect. Notes: https://lnkd.in/gCqHUeK9 #MachineLearning #XGBoost #LearningInPublic #Python #DataScience

📊 Not everything in data science is a finished project most of it is exploration. This is a small snapshot from my Jupyter Notebook while working through a project. At this stage, it’s not about perfect results it’s about: • Understanding the data • Trying different approaches • Visualizing patterns • Making sense of what’s happening underneath What looks like simple code on the screen is actually a process of trial, error, and discovery. 💡 Key takeaway: Before insights come confusion. Before clarity comes experimentation. Every notebook is just a record of how thinking evolves through data. #DataScience #Python #JupyterNotebook #DataAnalytics #LearningInPublic

#PrincipalComponentAnalysis (PCA) is more than just a technique for dimensionality reduction - it’s one of the most powerful applications of eigenanalysis in data science. By identifying the directions of maximum variance, PCA simplifies complex datasets while preserving their essential structure. What’s inside this guide: * The math: Covariance matrices and Eigen-decomposition.  * The logic: From data centering to explained variance.  * The code: Python realizations using NumPy and scikit-learn. Swipe through the carousel below to explore the mechanics of PCA! The link to the full #Medium article with complete code is in the first comment. #DataScience #MachineLearning #Python #LinearAlgebra #AI #STEM