Several excellent free data handling tools have come my way recently, at various presentations and conferences. This is an attempt at a short summary.
Graph data visualisers
I’ve already worked with Gephi, thanks to a Network basics course with Cornelia Reyes Acosta. Gephi is specifically designed to take columns of data and turn them into a network visualisation. It can also calculate several network metrics. It isn’t good at exporting for the web or for text; the best results are achieved by taking a screenshot and saving that as a PNG. This is an image I made for my networks course.
This blog post goes into more detail about displaying Gephi .gexf files on line. The trouble is that any sizeable graph is so large and detailed that just looking at it isn’t much use.
Google’s Fusion Tables is a web service that requires you to ahve a Google account (and wouldn’t work on Opera though it does on Firefox.) It imported my csv data table and allows me, amongst other things, to create a graph of suitable data. You can select which columns are ‘source’ and ‘target’ but
1. you can’t save it, just a link to it (and for this to work it has to be made public). So you’re back to taking screenshots and formatting them in GIMP then saving as pngs.
2. you can’t play around with formatting (sizes, colours, etc.)
3. it gives you no choice of layout algorithm and whatever one it is using looks add to me (compare Gephi chart – first one – with Google chart, of much the same data.)
Other numerical data displays
You can also submit data to RAWGraphs. This is written by Density Design, from the Politecnico di Milano. (The Director, Paolo Ciuccarrelli, spoke to the King’s meeting.) It has a great drag and drop interface. You upload your data and it produces immediate charts with minimal need for you to set them up. Charts can be downloaded as svg, png or json data. It handles many types of chart but does not appear to do graphs.
Voyant Tools offers several means of visualising text. You upload your text and choose your visualisaion type, and it does the rest online. You can download the results as png, or sometimes svg, though these are not interactive and you lose the nice sound effects from the ‘bubbles’ option!
Online Utility does basic ngram counts etc but returns the results simply as text which you can copy and paste:
Number of characters (including spaces) : 25354
Number of characters (without spaces) : 20125
Number of words : 4038
Lexical Density : 33.3086
Number of sentences : 198
Number of syllables : 6919
Do not confuse this site with utilities online which does similar things but more techie (eg a base 64 encoder/ decoder, xml/json converter).
Displaying large numbers of images together:
IMJ offers a limited range of image manipulations, turning sets of images into ‘barcodes’, ‘montages’ or ‘plots’, which can be downloaded as pngs. They take some time to work (though the site has a progress bar) and you have little control other than choosing one of the three types. I could not get ‘plots’ to work but this may be due to my PC settings as the other two did work.
Imageplot offers a download of software that will analyse and group images in similar ways to IMJ, as well as many other options. Basically again it takes a lot of iamges and arranges them on the page. It’s a 2MB download so I have not tried it yet, but there are screenshots of examples. This is produced by the US based Software Studies Initiative.
I won’t enlarge on d3 or jQueryas I have used them before. Both are quite complex to use and took me a while to get going. SigmaJS seems similar, less powerful and probably simpler. You download it and use it as a js include file. The website claims it can display .gexf graph files very simply, but I have not actually tried this.
Processing is a very powerfull programme that offers a lot of interactive options. See Generative Design, and its associated website, by Hartmut Bohnacker, Benedikt Gross, Julia Laub, and Claudius Lazzeroni, for examples. Also there is Form and Code, a book I haven’t bought, but which has a website too. I need to do some more work on Processing, and put up some examples here.
You can use your programmes directly on a PC, but if you want them on the internet the only way seems to be to use p5.js, a JS library that mimics processing in many respects, but runs directly on an HTML page and allows interactivity.