Archive for the ‘graphs’ Category

Graph Editor – yEd

Tuesday, January 29th, 2013

I wanted a graph editor where I could define the connectivity on-the-fly, including inserting new nodes partway along existing connections.  Something “fluid” to use.

I found it: yEd, available at http://www.yworks.com/en/products_yed_about.html.  Superbly slick, functional, multi-platform and free (gratuit), even for commercial use.

Main reason for wanting such a thing was to be able to document the media depenencies in a multimedia (e.g. video) project.  For example I might begin with an Adobe Premiere project based on raw footage.  I would document that in a connectivity-graph having a RawFootage node (object) with an arrowed line coming out of it and going into a Project node.  Later on, I might decide to enhance (e.g. CPU-intensively de-noise) the footage and then use that enhanced footage in the project instead (media-replace).  Such an intervention would not have been planned, it would have been an after-thought.  To bring my documentation up-to-date,  in my connectivity-graph, I would want to interpose an Enhance node in the existing footage-to-project connection.  Being able to do that in one single step would be great (no need for individual steps such as delete connection, add node, connect source to node, connect node to project).  Having made many such changes and additions over time, the diagram might become untidy and in need of rearrangement.  So ideally the application should offer Auto-Arrangement, to produce or at least provide a starting-point towards a tidier arrangement.

The same approach could apply to many things, including general brainstorming/mind-mapping, drama/story-design (prior to screenplays/scripts) and plain down-to-earth production of explanatory graphic diagrams as media themselves for incorporation in multimedia projects.

All this is way beyond the diagramming tool I have most used in the past few years, namely Visio – at least the (old) versions I have encountered.  I have dabbled with GraphViz, which auto-generates/arranges diagrams from formal connectivity (etc.) definitions in geeky formal notation.  GraphViz gets the job done but from my personal experience it is somewhat clunky and slow to use (involving frequent re-experiments and reading of lookup-notes).  I want something slicker, more “GUI”, more intuitive…

Haha!  Such a thing does exist!  I found it!  Not only does it allow the kind of graph-editing flexibility I am looking for, it can also import data from Excel etc. and auto-generate graphs from that.  So if I want I can document my connectivity/dependency information first in Excel or Notepad (say) with a view to generating a diagram from it at a subsequent stage.  And it is multi-platform (based on Java) and it is free (gratuit).

It is called yEd and is available at http://www.yworks.com/en/products_yed_about.html

(more…)

Slopegraph – In General and in R

Friday, July 15th, 2011

Slopegraph:

  • Suppose you have a table of two columns) and that you want to show graphically how the (two) elements of each row correspond in terms of value. A Slopegraph is useful in this context.
  • The originator, Edward Tufte (http://www.edwardtufte.com), says (http://www.edwardtufte.com/bboard/q-and-a-fetch-msg?msg_id=0003nk&topic_id=1) “Slopegraphs compare changes over time for a list of nouns located on an ordinal or interval scale.”  Basically: Any time you’d use a line chart to show a progression of univariate data among multiple actors over time, you might have a good candidate for a slopegraph.  But some people have found it useful beyond this context.

Links: