DataFrame is a tabular data structure for data analysis in Pharo. It organizes and represents data in a tabular format, resembling a spreadsheet or database table. It is designed to handle structured data and offer various functionalities for data manipulation and analysis. DataFrames are used as visualization tools for Machine Learning and Data Science related tasks.
To install the latest stable version of DataFrame (
pre-v3), go to the Playground (
Ctrl+OW) in your Pharo image and execute the following Metacello script (select it and press Do-it button or
EpMonitor disableDuring: [ Metacello new baseline: 'DataFrame'; repository: 'github://PolyMathOrg/DataFrame:pre-v3/src'; load ].
Use this script if you want the latest version of DataFrame:
EpMonitor disableDuring: [ Metacello new baseline: 'DataFrame'; repository: 'github://PolyMathOrg/DataFrame/src'; load ].
EpMonitor serves to deactive Epicea, a Pharo code recovering mechanism, during the installation of DataFrame.
How to depend on it?
If you want to add a dependency on
DataFrame to your project, include the following lines into your baseline method:
spec baseline: 'DataFrame' with: [ spec repository: 'github://PolyMathOrg/DataFrame/src' ].
If you are new to baselines and Metacello, check out the Baselines tutorial on Pharo Wiki.
What are data frames?
Data frames are the one of the essential parts of the data science toolkit. They are the specialized data structures for tabular data sets that provide us with a simple and powerful API for summarizing, cleaning, and manipulating a wealth of data sources that are currently cumbersome to use.
A data frame is like a database inside a variable. It is an object which can be created, modified, copied, serialized, debugged, inspected, and garbage collected. It allows you to communicate with your data quickly and effortlessly, using just a few lines of code. DataFrame project is similar to pandas library in Python or built-in data.frame class in R.
Very simple example
In this section I show a very simple example of creating and manipulating a little data frame. For more advanced examples, please check the DataFrame Booklet.
Creating a data frame
weather := DataFrame withRows: #( (2.4 true rain) (0.5 true rain) (-1.2 true snow) (-2.3 false -) (3.2 true rain)).
Removing the third row of the data frame
weather removeRowAt: 3.
Adding a row to the data frame
weather addRow: #(-1.2 true snow) named: 6.
Replacing the data in the first row and third column with 'snow'
weather at:1 at:3 put:#snow.
Transpose of the data frame
Documentation and Literature
- Data Analysis Made Simple with Pharo DataFrame - a booklet that serves as the main source of documentation for the DataFrame project. It describes the complete API of DataFrame and DataSeries data structures, and provides examples for each method.
- Zaytsev Oleksandr, Nick Papoulias and Serge Stinckwich. Towards Exploratory Data Analysis for Pharo In Proceedings of the 12th edition of the International Workshop on Smalltalk Technologies, pp. 1-6. 2017.