Hiona is a feature engineering system to correctly convert events into feature vectors for ML

It is a reactive system, akin to Kafka streams, but can be run more simply -- in a single docker container or lambda. for more details on Event-Driven Functional Reactive Progamming, see eg "Programming Paradigms for Dummies: What Every Programmer Should Know" by Peter Van Roy, the section on "Discrete synchronous programming" and surrounding context.

Using discrete time enormously simplifies programming for reactive systems. For example, it means that subprograms can be trivially composed: output events from one subcomponent are instantaneously available as input events in other subcomponents.

Getting started

Install a jdk (java 1.8 or java 11) and sbt:

e.g. on OSX with homebrew:

brew install homebrew/cask/java
brew install sbt

To run the tests, start sbt:

sbt

Which will give you the sbt command prompt. Enter compile to compile the code and test to run all the tests.

To format the code run scalafmtAll at the sbt prompt.

Running the example

At the sbt prompt, run assembly to build a "fat-jar" a jar with all dependencies in it. You can then run that using the java command:

java -jar target/scala-2.12/hiona-assembly-0.1.0-SNAPSHOT.jar

which should print the help message.

The command you want is run and you need to pass paths it asks for in show. E.g.

java -jar target/scala-2.12/hiona-assembly-0.1.0-SNAPSHOT.jar run --input hk-stocks=/home/oscar/Downloads/hk_prices_1h_2y_2017-06-20.csv --output results.csv

works on my machine.

To make changes, try changing Example.scala and then reissue the assembly command in the sbt prompt.

Running the benchmarks

At the sbt prompt:

bench/jmh:run -i 3 -wi 3 -f1 -t1 .*Bench.*

or use any regular expression to select the benchmark class you want to run. Change the parameters higher numbers for more reliable output, but longer running benchmarks.

IntelliJ

IntelliJ 2020.1 Beta (201.6668.13) (on Mac catalina) appears to correcly "create new project" for hiona (from github) ONLY after brew uninstall sbt -- brew's sbt seems to interfere with the proper import process, which results in eg build.sbt file being all red.

Python

We're targeting python 3.6 for simple scripting, without external libs. On a mac, follow instructions at homebrew-python github to install: brew install sashkab/python/python@3.6