The One Billion Row Challenge (1BRC) is a fun exploration of how far modern Java can be pushed for aggregating one billion rows from a text file. Grab all your…
Any post containing code examples
The Fast Fourier Transform (FFT) algorithm to calculate discrete Fourier transforms (DFT) is a recent addition to ojAlgo. The last blog post was about Image Processing (using Singular Value Decomposition,…
Suppose a satellite takes a picture and wants to send it to earth. The picture may contain 1000 by 1000 "pixels" – little squares each with a definite color. We…
https://lemire.me/blog/2022/11/22/what-is-the-size-of-a-byte-array-in-java Came across this blog post by Daniel Lemire. It's not his most interesting or informative post, but made me remember a little utility I wrote many years ago. MemoryEstimator…
The main benefit with ojAlgo's suite of mathematical optimisation solvers is that it's open source pure Java. It allows to solve mathematical optimisation problems directly in the JVM – no…
What is a Generalized AutoRegressive Conditional Heteroscedasticity (GARCH) process? That's a long fancy name for something that's actually relatively simple. The overall context is time series analysis. Let's sort out…
There are a number of different file formats around for persisting optimisation models, ojAlgo even has its own model file format. One of the file formats stands out as "the"…
A comparison between some iterative methods to solve linear equation systems. We'll compare 3 different methods: Jacobi, Gauss-Seidel and the Conjugate Gradient method. First the Jacobi and Gauss-Seidel methods are…
Imagine there's a sequence of operations you need to perform on a dataset, and this dataset is very large. There is absolutely no way the entire dataset could fit in…
With ojAlgo v51.2.0 the IntegerSolver gained support for Gomory Mixed Integer (GMI) cuts. Details of what they are and how they're derived is described in many publications. Just google it.…