Four dimensional spacetime datasets are created by the UKQCD group using a Monte Carlo method. These sets of data describe how gluons interact with each other. From these datasets various physical properties can be calculated, some of which will be mentioned later. The fact that these data sets are four dimensional complicates the visualisation. Because of this most existing visualisation occurs in the form of one dimensional graphs representing the evolution of a physical property with time. However this does not take full advantage of the four dimensional nature of the simulations and important properties may be overlooked by the user. Visualising gives the UKQCD group a new aspect on their data simply because it provides a new way of viewing it.
Visualisation of QCD data is a relatively new field. This means that the work carried out was a trial and error procedure. It was not known if visualisation of the properties was possible, nor if it would make any sense physically. The work done does provide a basic structure and background to the visualisation techniques available at EPCC. Hopefully this will lead to more properties being visualised, and give the physicist insight into previously hidden properties.
The first part of the project that this manual accompanies of involves combining the data to produce particles called mesons (this is covered in the first part of the report for this project). The data which result describe the motion of a particle that originated at a point in space (the centre of the data set). It is almost impossible to see what is happening to a three dimensional object by looking at two dimensional graph, so visualisation of the volume is important. Included in this manual are the details of how to go about creating and visualising mesons, starting with the original data taken from the QCD simulations.
The second part of the project looks at visualising the function used in the gauge fixing stage. This is a process that is carried out to make calculations easier (for a more detailed explanation of this please refer to report [1] that accompanies this project). Without visualisation of this property it is very hard to tell if this stage has been implemented correctly.
It is therefore an important part of both validating the simulations, and for further research, to be able to visualise the various physical properties in a variety of ways.