Tomas Petricek

Searching for new ways of thinking in programming & working with data

I believe that the most interesting work is not the one solving hard problems, but the one changing how we think about the world. I follow this belief in my work on data science tools, functional programming and F# teaching, in my programming languages research and I try to understand it through philosophy of science.

The Gamma

I'm working on making data-driven storytelling easier, more open and reproducible at the Alan Turing Institute.

Consulting

I'm author of definitive F# books and open-source libraries. I offer my F# training and consulting services as part of fsharpWorks.

Academic

I published papers about theory of context-aware programming languages, type providers, but also philosophy of science.

Tomas Petricek
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Creating interactive You Draw bar chart with Compost

For a long time, I've been thinking about how to design a data visualization library that would make it easier to compose charts from simple components. On the one hand, there are charting libraries like Google Charts, which offer a long list of pre-defined charts. On the other hand, there are libraries like D3.js, which let you construct any data visualization, but in a very low-level way. There is also Vega, based the idea of grammar of graphics, which is somewhere in between, but requires you to specify charts in a fairly complex language including a huge number of transformations that you need to write in JSON.

In the spirit of functional domain specific languages, I wanted to have a small number of simple but powerful primitives that can be composed by writing code in a normal programming language like F# or JavaScript, rather than using JSON.

My final motivation for working on this was the You Draw It article series by New York Times, which uses interactive charts where the reader first has to make their own guess before seeing the actual data. I wanted to recreate this, but for bar charts, when working on visualizing government spending using The Gamma.

The code for this was somewhat hidden inside The Gamma, but last month, I finally extracted all the functionality into a new stand-alone library Compost.js with simple and clean source code on GitHub and an accompanying paper draft that describes it (PDF).

In this article, I will show how to use Compost.js to implement a "You Draw" bar chart inspired by the NYT article. When loaded, all bars show the average value. You have to drag the bars to positions that you believe represent the actual values. Once you do this, you can click "Show me how I did" and the chart will animate to show the actual data, revealing how good your guess was. Before looking at the code, you can have a look at the resulting interactive chart, showing the top 5 areas from the 2015 UK budget (in % of GDP):

Published: Thursday, 16 July 2020, 10:20 PM
Tags: functional, functional programming, data science, thegamma, data journalism, visualization
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Getting started with The Gamma just got easier

Over the last year, I have been working on The Gamma project, which aims to make data-driven visualizations more trustworthy and to enable large number of people to build visualizations backed by data. The Gamma makes it possible to create visualizations that are built on trustworthy primary data sources such as the World Bank and you can provide your own data source by writing a REST service.

A great piece of feedback that I got when talking about The Gamma is that this is a nice ultimate goal, but it makes it hard for people to start with The Gamma. If you do not want to use the World Bank data and you're not a developer to write your own REST service, how do you get started?

To make starting with The Gamma easier, the gallery now has a new four-step getting started page where you can upload your data as a CSV file or paste it from Excel spreadsheet and create nice visualizations that let your reader explore other aspects of the data.

Head over to The Gamma Gallery to check it out or continue reading to learn more about creating your first The Gamma visualization...

Published: Wednesday, 14 June 2017, 1:27 PM
Tags: thegamma, data journalism, data science, research, visualization
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The Gamma dataviz package now available!

There were a lot of rumors recently about the death of facts and even the death of statistics. I believe the core of the problem is that working with facts is quite tedious and the results are often not particularly exciting. Social media made it extremely easy to share your own opinions in an engaging way, but what we are missing is a similarly easy and engaging way to share facts backed by data.

This is, in essence, the motivation for The Gamma project that I've been working on recently. After several experiments, including the visualization of Olympic medalists, I'm now happy to share the first reusable component based on the work that you can try and use in your data visualization projects. If you want to get started:

  • Check out thegamma-script package on npm
  • Minimal example of thegamma-script in action
  • How to use thegamma-script in your projects

The package implements a simple scripting language that anyone can use for writing simple data aggregation and data exploration scripts. The tooling for the scripting language makes it super easy to create and modify existing data analyses. Editor auto-complete offers all available operations and a spreadsheet-inspired editor lets you create scripts without writing code - yet, you still get a transparent and reproducible script as the result.

Published: Wednesday, 25 January 2017, 12:31 PM
Tags: thegamma, data journalism, data science, research, visualization
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Happy New Year 2016 around the World: Behind the scenes of my #FsAdvent project

Just like last year and the year before, I wanted to participate in the #FsAdvent event, where someone writes a blog post about something they did with F# during December. Thanks to Sergey Tihon for the organization of the English version and the Japanese F# community for coming up with the idea a few years ago!

As my blog post ended up on 31 December, I wanted to do something that would fit well with the theme of ending of 2015 and starting of the new year 2016 and so I decided to write a little interactive web site that tracks the "Happy New Year" tweets live across the globe. This is partly inspired by Happy New Year Tweets from Twitter in 2014, but rather than analyzing data in retrospect, you can watch 2016 come live!

Published: Wednesday, 30 December 2015, 6:09 PM
Tags: f#, data journalism, thegamma, data science, visualization
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Please submit issues & corrections on GitHub. Use pull requests for minor corrections only.

  • Twitter: @tomaspetricek
  • GitHub: @tpetricek
  • Email me: tomas@tomasp.net

Blog archives

October 2020 (1),  July 2020 (1),  April 2020 (2),  December 2019 (1),  February 2019 (1),  November 2018 (1),  October 2018 (1),  May 2018 (1),  September 2017 (1),  June 2017 (1),  April 2017 (1),  March 2017 (2),  January 2017 (1),  October 2016 (1),  September 2016 (2),  August 2016 (1),  July 2016 (1),  May 2016 (2),  April 2016 (1),  December 2015 (2),  November 2015 (1),  September 2015 (3),  July 2015 (1),  June 2015 (1),  May 2015 (2),  April 2015 (3),  March 2015 (2),  February 2015 (1),  January 2015 (2),  December 2014 (1),  May 2014 (3),  April 2014 (2),  March 2014 (1),  January 2014 (2),  December 2013 (1),  November 2013 (1),  October 2013 (1),  September 2013 (1),  August 2013 (2),  May 2013 (1),  April 2013 (1),  March 2013 (1),  February 2013 (1),  January 2013 (1),  December 2012 (2),  October 2012 (1),  August 2012 (3),  June 2012 (2),  April 2012 (1),  March 2012 (4),  February 2012 (5),  January 2012 (2),  November 2011 (5),  August 2011 (3),  July 2011 (2),  June 2011 (2),  May 2011 (2),  March 2011 (4),  December 2010 (1),  November 2010 (6),  October 2010 (6),  September 2010 (4),  July 2010 (3),  June 2010 (2),  May 2010 (1),  February 2010 (2),  January 2010 (3),  December 2009 (3),  July 2009 (1),  June 2009 (3),  May 2009 (2),  April 2009 (1),  March 2009 (2),  February 2009 (1),  December 2008 (1),  November 2008 (5),  October 2008 (1),  September 2008 (1),  June 2008 (1),  March 2008 (3),  February 2008 (1),  December 2007 (2),  November 2007 (6),  October 2007 (1),  September 2007 (1),  August 2007 (1),  July 2007 (2),  April 2007 (2),  March 2007 (2),  February 2007 (3),  January 2007 (2),  November 2006 (1),  October 2006 (3),  August 2006 (2),  July 2006 (1),  June 2006 (3),  May 2006 (2),  April 2006 (2),  December 2005 (1),  July 2005 (4),  June 2005 (5),  May 2005 (1),  April 2005 (3),  March 2005 (3),  January 2005 (1),  December 2004 (3),  November 2004 (2), 

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