Every city needs energy in various forms like gas or
oil. The energy gets distributed within the city and is transformed
into heat or electricity, for example. Those energies are going to propel the
citizens electrical devices, heat their houses and move their cars.
As time passes by and energy technologies evolve, the energy footprint of
a city changes. The main points of interest are questions like how the
energy is distributed, where are the hugest losses and
what kind of energy is used for which purpose.
In other words engineers are interested in the specific energy flow of a
city. Typically, the underlying dataset is a spreadsheet that constists of thousands of
values and equations which in a whole describe the energy flow network.
This is a representation that is very hard to interpret and to
deal with. Especially when less involved people want to have an insight.
Those people can be normal citizens that just want
to inform themselves. The managment staff of an energy company wants to
discover trends in the energy market to optimize their business. Politicians
must have an overview of the energy structure of a city, because they have
to make decisions: What part of the energy structure could be changed, for example
to minimize carbone-dioxid emissions?
To support the understanding of the energy structure, the data is visualized in special diagrams, the so called
These diagrams represent the energy flow as a graph and the particular amount
of energy as thickness of the edges. Usually the diagrams are assembled by hand which is
an arduously and error prone work.
Therefore, society could greatly benfit from a tool that creates interactive and
dynamic sankey-diagrams automatically, to ease the interpretation an exploration
of energy strutures, leading to a better understanding. The creation of such a
tool is the aim of this project.
The tool that we have developed is splitted into a modeling and a rendering
component. The modeling component is a graph editor which
is used to specify the dependencies and values of the energy flow and
furthermore sets some rendering hints. The output of the modeler is
then visualized by the renderer. Additionally the renderer serves as
the user interface to make interactions with the sankey-diagram
Popup menus for detailed information on components of
the sankey-diagram are supported. Edges can be selected and promoted to the
foreground to improve the readability if necessary. Focus and context is
used for zooming and navigation.
|© 2004 · Patrick Riehmann, Moritz Goellner, Henrik Thoms · email|