Algorithms

Markov Chains explained visually

Markov chains are mathematical systems that model transitions between different states with associated probabilities, represented through transition matrices or diagrams. The concept finds practical applications in various fields, from weather prediction to Google's PageRank algorithm, with the ability to simulate real-world phenomena by incorporating probabilistic state transitions.

Sublinear Time Algorithms

Sublinear time algorithms represent a paradigm shift in computational efficiency, allowing processing of extremely large datasets by reading only a fraction of the input. While exact deterministic sublinear algorithms exist for some problems, most solutions require randomization and approximation techniques, with applications spanning optimization, property testing, and distribution analysis.

On word embeddings - Part 3: The secret ingredients of word2vec

An in-depth analysis reveals that word embedding models like word2vec aren't inherently superior to traditional distributional semantic methods, with hyperparameter optimization being more crucial than algorithm choice. The study demonstrates that Singular Value Decomposition (SVD) often outperforms popular embedding methods in word similarity tasks, while Skip-gram Negative Sampling (SGNS) excels in analogy tasks.

Tiny Pointers

A novel data structure called 'tiny pointer' is introduced, enabling the replacement of traditional logn-bit pointers with o(logn)-bit pointers while maintaining constant-factor time overhead. The research presents optimal constructions for both fixed-size and variable-size tiny pointers, demonstrating practical applications in five classic data structure problems.

Writing My Own Dithering Algorithm in Racket

An exploration of image dithering techniques demonstrates how to convert color images to black-and-white using various algorithms, including a novel approach that balances between Atkinson and Floyd-Steinberg methods. The author developed this technique while building Guten, a custom newspaper printer that requires monochrome images, showcasing practical applications of dithering in modern technology.

the sudoku affair

A comparative analysis of two different approaches to building a Sudoku solver highlights how Peter Norvig's constraint propagation solution proved more effective than Ron Jeffries' incremental design approach. The core difference lay in their data representations - Norvig used a map of possible moves while Jeffries used a list mimicking the visual board, demonstrating how fundamental design choices impact solution elegance and extensibility.