Java object analogue to R data.frame [closed]

Answer 1

I have just open-sourced a first draft version of Paleo, a Java 8 library which offers data frames based on typed columns (including support for primitive values). Columns can be created programmatically (through a simple builder API), or imported from text file.

Please refer to the README for further details.

The project is still wet from birth – I am very interested in feedback / PRs, tia!

Answer 2

I also found myself in need of a data frame structure while working in Java recently. Fortunately, after writing a very basic implementation I was able to get approval to release it as open source. You can find my implementation here: Joinery -- Data frames for Java. Contributions and feature requests are welcome.

Answer 3

Not being very proficient with R, but you should have a look at Guava, specifically Tables. They do not provide the exact functionality you want, but you could either extend them or their specification could help you in writing your own Collection.

Answer 4

Tablesaw (https://github.com/jtablesaw/tablesaw) is Java dataframe begun in 2015 and is under active development (2018). It's designed to be as scalable as possible without sacrificing ease-of-use. Features include filtering by rows and columns, descriptive stats, map/reduce functions, cross-tabs, plots, machine learning. Apache license.

In one query test it returned 500+ records from a 1/2 billion record table in 2 ms.

Contributions, feature requests, and feedback are welcome.

Answer 5

Morpheus (http://www.zavtech.com/morpheus/docs/) provides a DataFrame analogue to that of R. It is a high performance column store data structure that enables data to sorted, sliced, grouped, and aggregated in either the row or column dimension. It also supports parallel processing for many of these operations using the Fork & Join framework internally.

You can easily read & write data to CSV files, databases and also a proprietary JSON format. Adapters to load data from Quandl, Google Finance and others are also available.

It has built in support for various styles of Linear Regressions, Principal Component Analysis, Linear Algebra and other types of analytics support. The feature set is still growing, but it is already a very capable framework.

Answer 6

In R we have the dataframe, in Python we have pandas, in Java: There is the Schema from the deeplearning4j

There is also a version for the data analysis of the ubiquitous iris data if you want to just get started, here

There are also other custom objects (from Weka, from Tensorflow that are more or less the same).