K-means is an essential algorithm for Data Science.
But it's confusing for beginners.
Let me demolish your confusion:
1. K-Means
K-means is a popular unsupervised machine learning algorithm used for clustering. It's a core algorithm used for customer segmentation, inventory categorization, market segmentation, and even anomaly detection.
2. Unsupervised:
K-means is an unsupervised algorithm used on data with no labels or predefined outcomes. The goal is not to predict a target output, but to explore the structure of the data by identifying patterns, clusters, or relationships within the dataset.
3. Objective Function:
The objective of K-means is to minimize the within-cluster sum of squares (WCSS). It does this though a series of iterative steps that include Assignments and Updated Steps.
4. Assignment Step:
In this step, each data point is assigned to the nearest cluster centroid. The "nearest" is typically determined using the Euclidean distance.
5. Update Step:
Recalculate the centroids as the mean of all points in the cluster. Each centroid is the average of the points in its cluster.
6. Iterate Step(s):
The assignment and update steps are repeated until the centroids no longer change significantly, indicating that the clusters are as good as stable. This process minimizes the within-cluster variance.
7. Silhouette Score (Evaluation):
This metric measures how similar a data point is to its own cluster compared to other clusters. The silhouette score ranges from -1 to 1, where a high value indicates that the data point is well-matched to its own cluster and poorly matched to neighboring clusters.
8. Elbow Method (Evaluation):
This method involves plotting the inertia as a function of the number of clusters and looking for an 'elbow' in the graph. The elbow point, where the rate of decrease sharply changes, can be a good choice for the number of clusters.
9. There's a new problem that has surfaced --
Companies NOW want AI.
AI is the single biggest force of our decade. Yet 99% of data scientists are ignoring it.
That's a huge advantage to you. I'd like to help.
Want to become a Generative AI Data Scientist in 2025 ($200,000 career)?
On Wednesday, Sept 3rd, I'm sharing one of my best AI Projects: How I built an AI Customer Segmentation Agent with Python
These 7 statistical analysis concepts have helped me as an AI Data Scientist.
Let's go: 🧵
Step 1: Learn These Descriptive Statistics
Mean, median, mode, variance, standard deviation. Used to summarize data and spot variability. These are key for any data scientist to understand what’s in front of them in their data sets.
2. Learn Probability
Know your distributions (Normal, Binomial) & Bayes’ Theorem. The backbone of modeling and reasoning under uncertainty. Central Limit Theorem is a must too.
Linear Regression is one of the most important tools in a Data Scientist's toolbox.
Yet it's super confusing for beginners.
Let's fix that: 🧵
1. Ordinary Least Squares (OLS) Regression
Most common form of Linear Regression. OLS regression aims to find the best-fitting linear equation that describes the relationship between the dependent variable (often denoted as Y) and independent variables (denoted as X1, X2, ..., Xn).
2. Minimize the Sum of Squares
OLS does this by minimizing the sum of the squares of the differences between the observed dependent variable values and those predicted by the linear model. These differences are called "residuals."
🚨BREAKING: New Python library for agentic data processing and ETL with AI
Introducing DocETL.
Here's what you need to know:
1. What is DocETL?
It's a tool for creating and executing data processing pipelines, especially suited for complex document processing tasks.
It offers:
- An interactive UI playground
- A Python package for running production pipelines
2. DocWrangler
DocWrangler helps you iteratively develop your pipeline:
- Experiment with different prompts and see results in real-time
- Build your pipeline step by step
- Export your finalized pipeline configuration for production use