techblog 

Over the past few months I have been working with Iris Explorer to develop visualisation applications. Iris Explorer uses a module based approach to application development, where tasks are split into individual modules which can be then wired together. The modules represent processes on the data and the wires between them represent the flow of the data between the modules. A simple drag and drop interface is provided for adding and linking the components of an application, or map, together.

Iris Explorer is distributed with a set of standard modules for accomplishing a wide variety of standard tasks such as, reading data, writing images, and standard visualisation techniques, such as plotting histograms. An example of an Iris Explorer map is shown below:

I have been working on creating a 3D graph to represent the volume of queries to our WHOIS system for each hour of a given date, or range of dates. This could largely be accomplished using the standard module set avaialble with Iris Explorer, however there were no modules for the labelling of the axes of graphs which were particularly suited to the task, which meant I had to write my own custom module.

Iris Explorer provides the ability to write your own modules, so it is entirely possible to add custom processes and functionality to an application. The method for developing these custom modules is a two step process, first of all the the layout of the module is defined using the Iris Module Builder, secondly a user function, written in C/C++, is added.

The Module Builder provides a GUI to creating the module window, its data input and output ports and specifying the flow of data through the module internally. This is a logical process where you simply specify the type of input data which is accepted as well as the format of the output data. The appearance of the module itself and the user interface of the module are also specified using a drag and drop WYSIWYG style editor.

The second stage, the user function, controls the processing of the data. So in the case of the Graph Labelling module I have written this would extract the number of dimensions in the data set and number bars of the graph accordingly, as well as creating and positioning axis text labels.

The Iris Explorer Map produced collects data for a given date range, and split this into hourly segments to give a clear picture of the volume of queries to our systems at any given hour of the day. An example of the results of this are shown below: