frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

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•6mo 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•6mo 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•6mo 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•6mo 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•6mo 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•6mo ago
Polars and duckdb interoperate nicely and can enable this flexibility
theanonymousone•6mo ago
Does Polars have a Java library?
mousomashakel•6mo 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.
theanonymousone•6mo 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•6mo 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.
skanga•6mo ago
What about Tablesaw, Apache Arrow? How does this compare ...
mousomashakel•6mo 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•6mo ago
Nice!

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

mousomashakel•6mo 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.

Show HN: ChunkBack – A Fake LLM API server for testing apps without paying

https://github.com/4shub/chunkback
3•forthwall•34m ago•0 comments

Show HN: Browser-based interactive 3D Three-Body problem simulator

https://trisolarchaos.com/?pr=O_8(0.6)&n=3&s=5.0&so=0.00&im=rk4&dt=1.00e-4&rt=1.0e-6&at=1.0e-8&bs...
194•jgchaos•1d ago•79 comments

Show HN: Vibe Prolog

https://github.com/nlothian/Vibe-Prolog
4•nl•1h ago•0 comments

Show HN: RowboatX – open-source Claude Code for everyday automations

https://github.com/rowboatlabs/rowboat
104•segmenta•21h ago•39 comments

Show HN: Fixing a single pointer bug unlocked 1M+ row JSON parsing on Windows

4•hilti•3h ago•0 comments

Show HN: Guts – convert Golang types to TypeScript

https://github.com/coder/guts
92•emyrk•22h ago•26 comments

Show HN: A subtly obvious e-paper room air monitor

https://www.nicolin-dora.ch/blog/en-epaper-room-air-monitor-part-1/
58•nomarv•1d ago•24 comments

Show HN: Open-source library to get detailed power and system info for Macs

https://github.com/BinSquare/powermetrics-go
3•binsquare•4h ago•0 comments

Show HN: I built a synth for my daughter

https://bitsnpieces.dev/posts/a-synth-for-my-daughter/
1258•random_moonwalk•1w ago•209 comments

Show HN: Q⊗DASH – Rust/Python quantum operator framework for graph-based QC

3•dioniceOS•4h ago•0 comments

Show HN: Excel Custom Functions in Zig

https://github.com/AlexJReid/zigxll
4•alexjreid•5h ago•0 comments

Show HN: Parqeye – A CLI tool to visualize and inspect Parquet files

https://github.com/kaushiksrini/parqeye
157•kaushiksrini•1d ago•35 comments

Show HN: Godantic – JSON Schema and Validation for Go LLM Apps

https://github.com/deepankarm/godantic
2•deepankarm44•5h ago•0 comments

Show HN: ESPectre – Motion detection based on Wi-Fi spectre analysis

https://github.com/francescopace/espectre
203•francescopace•2d ago•50 comments

Show HN: Continuous Claude – run Claude Code in a loop

https://github.com/AnandChowdhary/continuous-claude
161•anandchowdhary•4d ago•59 comments

Show HN: Tokenflood – simulate arbitrary loads on instruction-tuned LLMs

https://github.com/twerkmeister/tokenflood
20•twerkmeister•1w ago•0 comments

Show HN: Reversing a Cinema Camera's Peripherals Port

https://3nt3.de/blog/reversing-fs7-comms
47•3nt3•1w ago•2 comments

Show HN: Lumical – scan any meeting invite into your calendar in seconds

https://lumical.app/
3•arunavo4•9h ago•4 comments

Show HN: PrinceJS – 19,200 req/s Bun framework in 2.8 kB (built by a 13yo)

https://princejs.vercel.app
148•lilprince1218•1d ago•68 comments

Show HN: Kk – A tiny Bash CLI that makes kubectl faster

https://github.com/heart/kk-Kubernetes-Power-Helper-CLI
2•nkheart•10h ago•0 comments

Show HN: Startup Simulator

https://startup-simulator-phi.vercel.app/
3•paperplaneflyr•13h ago•2 comments

Show HN: Kalendis – Scheduling API (keep your UI, we handle timezones/DST)

https://kalendis.dev
18•dcabal25mh•1d ago•8 comments

Show HN: Building WebSocket in Apache Iggy with Io_uring and Completion Based IO

https://iggy.apache.org/blogs/2025/11/17/websocket-io-uring/
29•spetz•1d ago•6 comments

Show HN: My hobby OS that runs Minecraft

https://astral-os.org/posts/2025/10/31/astral-minecraft.html
14•avaliosdev•1d ago•3 comments

Show HN: Unflip – a puzzle game about XOR patterns of squares

https://unflipgame.com/
179•bogdanoff_2•1w ago•52 comments

Show HN: Bsub.io – zero-setup batch execution for command-line tools

22•wkoszek•2d ago•10 comments

Show HN: Octopii, a framework for building distributed applications in Rust

21•janicerk•2d ago•3 comments

Show HN: I released Steam utility "Sentinel Signal" to manage your gaming time

https://store.steampowered.com/app/3879010/Sentinel_Signal/
2•sentinelsignal•7h ago•0 comments

Show HN: How are Markov chains so different from tiny LLMs?

17•JPLeRouzic•1d ago•1 comments

Show HN: Agfs – Aggregated File System, a modern tribute to the spirit of Plan9

https://github.com/c4pt0r/agfs
9•c4pt0r•1d ago•0 comments