frontpage.
newsnewestaskshowjobs

Open Source @Github

fp.

Open in hackernews

Show HN: Fahmatrix – A Lightweight, Pandas-Like DataFrame Library for Java

https://github.com/moustafa-nasr/fahmatrix
46•mousomashakel•1y ago
Hey HN, I’ve built Fahmatrix, a minimal, fast Java library for working with tabular data — inspired by Python’s pandas, but designed for performance and simplicity on the JVM.

After working extensively with Python’s data stack, I often ran into limitations related to speed, especially in larger or long-running data workflows. So I built Fahmatrix from scratch to offer similar APIs for manipulating CSVs, performing summary statistics, slicing rows/columns, and more — but all in Java.

Features:

Lightweight and dependency-free

CSV/TSV import with auto-headers

Series/DataFrame structures (like pandas)

describe(), mean(), stdDev(), percentile() and more

Fast parallel operations on numeric columns

Java 17+ support

Docs: https://moustafa-nasr.github.io/Fahmatrix/ GitHub: https://github.com/moustafa-nasr/fahmatrix

I’d love feedback from the Java and data communities — especially if you’ve ever wanted a simple dataframe utility in Java without needing full-scale ML libraries.

Happy to answer any questions!

Comments

rickette•1y ago
Congrats on putting this out there. There isn't a de facto pandas-like library in Java like you said. But for Kotlin there is: https://github.com/Kotlin/dataframe
mousomashakel•1y ago
Thanks so much! Yep, I’ve seen the Kotlin DataFrame lib — very elegant. Fahmatrix is meant for plain Java users who want similar capabilities without switching ecosystems. Appreciate the support!
uwemaurer•1y ago
Always great to see efforts to make working with data frames easier. Here are some similar data frame libraries for Java:

https://github.com/jtablesaw/tablesaw

https://github.com/dflib/dflib

My preferred way is just use duckdb java API. I didn't see anything better in performance/efficiency. Also a SQL query is often easier to write

theanonymousone•1y ago
Yes. It has bothered me for a long time too. Maybe the best mix is a dataframe library with basic operations (column select, non-null etc), which also allows SQL for more complex stuff?
radus•1y ago
Polars and duckdb interoperate nicely and can enable this flexibility
theanonymousone•1y ago
Does Polars have a Java library?
mousomashakel•1y ago
Totally agree that SQL can be the best tool for many jobs. My goal with Fahmatrix is to serve the opposite niche: where devs want something that's Java-native, procedural, and simple without reaching for an external engine. SQL support or DSL might come later though — I see the appeal.
skanga•1y ago
What about Tablesaw, Apache Arrow? How does this compare ...
mousomashakel•1y ago
Good question. I’ll publish benchmarks soon, but the core difference is that Fahmatrix is fully Java, no JNI, and minimalistic — ideal for small projects or environments like Android. Tablesaw and Arrow are more powerful, but heavier. Fahmatrix aims to be the “just enough” middle ground.
owlstuffing•1y ago
Nice!

I’m currently using manifold-sql with duckdb for this.

mousomashakel•1y ago
Thanks! That’s a great combo — manifold-sql + duckdb gives you strong typing with powerful SQL under the hood. Fahmatrix is aiming to complement that approach for cases where you want quick, native Java code without SQL — e.g., when building data flows or custom logic inline. Would love to hear if you’ve hit any pain points that a Java-native approach could help with.
theanonymousone
•
1y ago
Sure. So maybe notehr comment would be to make it (particularly the Series class), as compatible with Java Streams as possible.

Next step would likely be compatibility with popular libraries such as Apache Commons Math: https://commons.apache.org/proper/commons-math/userguide/sta...

mousomashakel•1y ago
Thanks! I'm aware of those great projects. Fahmatrix aims to offer a lightweight, dependency-free alternative that’s easy to embed in any Java app. DuckDB is super impressive, especially for SQL-heavy tasks — but my goal is more about a native, fluent API for those who prefer direct Java code over SQL.

Show HN: Sarala – An open-source WYSIWYG Markdown editor

https://sarala.solancer.com/
3•solancer•35m ago•0 comments

Show HN: TurboGPT: train 22KiB transformer in 13s

https://github.com/lostmsu/TurboGPT
2•lostmsu•37m ago•0 comments

Show HN: Jevstiller – Distill Jev into a local model, with a disagreement bound

https://jevstiller.pages.dev/posts/the-guarantee/
52•tgluck•7h ago•7 comments

Show HN: Real-time Solar System with 526k asteroids and all tracked satellites

https://space.bl2.net/
3•wanick•49m ago•3 comments

Show HN: A working 3D model of an Enigma machine

https://enigma.design
8•primitivesuave•2h ago•0 comments

Show HN: HN.watch – Videos of all Hacker News posts

https://hn.watch/
206•mrborgen•1d ago•97 comments

Show HN: Destroy Any Website with Stickman

https://destroy.spritefusion.com/
163•HugoDz•1d ago•37 comments

Show HN: Free browser games designed for 80-year-old eyes and hands

https://freegamesforseniors.com/
5•xmasdong•4h ago•0 comments

Show HN: NSL – WSL for Linux

https://frostyard.github.io/nsl/
58•bketelsen•5h ago•45 comments

Show HN: PaperMono, e-ink fridge magnet shopping list with mobile web page

https://github.com/seamusc/papermono-shopping-list
145•seamus_c•1d ago•61 comments

Show HN: Free alternative to graphics design giants

https://scissor.studio/
130•sia_xi•1d ago•50 comments

Show HN: Sezwhere – Ask any document "where does it say that?" (built on Jev)

https://sezwhere.com/
8•irs•5h ago•1 comments

Show HN: Ctxfw – AST context firewall that cuts agent prompt tokens by 67%

https://github.com/heuristicolab/ctxfw
5•mikemo88•5h ago•0 comments

Show HN: Pac-Bench – How well can models one-shot a Pac-Man game?

https://jonclegg.github.io/pacman-bakeoff/
77•thefourthchime•21h ago•47 comments

Show HN: We built a way for web apps to message users' phones without SMS

https://thenotifier.app/developers/
7•bubbamack•5h ago•9 comments

Show HN: Misanthropic – an AI that's honest about how it feels about you

https://misanthropic.chat
5•yaskyj•5h ago•3 comments

Show HN: Museum of Numbers

https://numbermuseum.com/2147483647
30•rhl314•3d ago•12 comments

Show HN: NetWasm – Independent .NET Compiler/Runtime (82.5 KB Hello World in C#)

https://playground.netwasm.com/
5•zionsati•6h ago•4 comments

Show HN: Last Internet Connection

https://reparadoxy.itch.io/last-internet-connection
2•PolishDevelop22•2h ago•0 comments

Show HN: CodeDiff – Fast (<100ms), robust (99.95%) syntax-aware code diff

https://github.com/ivankovic/codediff
4•FabCH•7h ago•0 comments

Show HN: Lofi Cities – Pixel-art city nights with browser-generated lofi

https://loficities.com/
313•safaelmali•2d ago•135 comments

Show HN: Bough, Visualize your vibe coded project: progress, time, cost and more

https://github.com/nickelsec/bough
3•nikhilkxmar•7h ago•0 comments

Show HN: Jev Plays Pokémon Red

https://jev-pokemon.vercel.app/
281•pancomplex•4d ago•123 comments

Show HN: Raven – The harness of harnesses, built for RSI

https://github.com/EverMind-AI/Raven
52•cyfyifanchen•9h ago•46 comments

Show HN: TinyAIArena watch AI agents battle it out

https://tinyaiarena.com/
119•hp6•2d ago•45 comments

Show HN: A goal tracker that looks like a 1983 terminal, drawn in Swift

https://apps.apple.com/us/app/thrive-habit-goal-tracker/id6768297854
7•NSergeevich•11h ago•1 comments

Show HN: Hntui – A TUI for Hacker News

https://github.com/ahmd-sh/hntui
111•ahmd-sh•1d ago•65 comments

Show HN: Reladraw – A diagram language where you decide where to place things

https://github.com/reladraw/reladraw
406•jpwalsh234•3d ago•119 comments

Show HN: Open-source skills for end-to-end video ad campaigns

https://github.com/SupercmoHQ/superCMO-skills
7•sayonidroy•13h ago•0 comments

Show HN: Interactive Diesel Price Forecaster

https://sightspinner.ai/blog/diesel-prices-are-high-here-s-why-they-might-go-higher-2026-09-29.html
7•sightspinner•18h ago•0 comments