Included with the Data Logger software is the BPMpro Body Data Analyser which has been created using Excel, Visual Basic and macro tools to help users in interpreting the extensive data output from the BPMpro Data Logger by organising and displaying the data quickly and easily. By using Excel, it also means that the user can understand how to load up specific BPMpro Data if they wish to build their own data analysis spreadsheets.
The BPMpro Data Logger is a powerful movement data collection tool, quite often, however, it is not the actual data, but the trends and differences between the data that are more important. The Data Analyser workbook has a number of tabs that contain the source data from the selected files as well as a number of screens, but all the data import and display selection is driven by the Chart Display screen shown below:
The Analyser allows the user to quickly and easily select different data files, different parameters from those files and to compare the results against files from different sources or from different points in time. On the Chart Display tab there are two displays so that data with different vertical scales can be displayed at the same time. Excel does not support dual axes so it is not possible to mix different vertical scales on the same graph. The dual graphs do, however, allow you to view completely different data at the same time and to view differential data where one set of data is added or subtracted from the other. For example, the data from one athlete can be quickly compared to that of another and different aspects of their motion subsequently studied in further detail so that the coach can understand from where differences in performance are derived. On the large chart tab there are dual graphs so that data with different vertical scales can be displayed at the same time, different data can be reviewed at the same time and differential data where one set of data is added or subtracted from the other can be seen.
The Data Analyser has a number of powerful features to enable data analysis:
- Zoom In/Out – the Analyser has been designed to make it simple to zoom in on data points, either in 5 second steps or by zooming straight into a one second view in the middle of the timeline. Similarly the Zoom Out function allows the user to zoom out in either 5 second steps or straight back to the full view.
- Movable Timeline – the period of time displayed can be moved backwards and forwards either in one second blocks or to the start or end of the timeline whilst retaining the applied level of zoom.
- Statistical data – the Large Chart screen also shows statistical information on what is displayed: range, average, mean, maximum, minimum and frequency.
- Data Playback – the displayed data can replayed in full screen so that the user can see how the selected parameters interact in real time.
- Data Alignment – the Offset feature permits the synchronisation of the starting points of data where they vary between data sources.
- Data Conversion – when the Analyser reads in data files, some automated data conversion takes place to make certain data parameters easier to work with. For example, the orientation data output from the Data Logger is changed from vector units into degrees which are more widely understood.
- Data Calculation – when data files are read in, the Analyser additionally calculates extra parameters such as continuous angles for x, y and z axis movements.
- Differential Analysis – the Function feature enables the user to quickly carry out subtraction and addition functions to highlight the difference between different sets of data.