Abstract: The invention provides a data visualisation system comprising a data value memory in which is maintained a finite set of data values and display means arranged to display a contoured representation. One or more of the data values are displayed as contours around one or more data points and each data value is centred on a data point. The invention also provides a method of data visualisation and a data visualisation computer program.

Abstract: The invention provides a trading data visualisation system comprising a transaction database stored in computer memory of transaction data representing transactions in relation to one or more tradable items, the transaction data comprising one or more data sets, one or more of the data sets comprising an item identifier, a transaction identifier and an item volume value. The system also includes a retrieval component configured to retrieve transaction data from the transaction database and a display configured to display one or more graphical representations of some or all of the transaction data, the size of one or more of the graphical representations proportional to the volume of tradable items represented by the transaction data. The invention also provides related methods of visualising trading data.