Tutorial 4-How to Create a Polyviz widget using Orange

Polyviz widget in Orange

Polyviz is a visualization technique used in Orange where the various data points are related to anchors with value dependent positions. A comparison of various anchors or attributed can be made visually showing the comparison of data points by pinpointing each data point with respect to its attribute. It can be applied in electoral analysis, analyzing spread of epidemics, sales distribution of goods and so on. In the tutorial the data set shows the different age groups and their type of prescription lens, whether they are astigmatic (caused by irregular shape of cornea) tear rate of the lens and finally type of lenses used. If they are astigmatic a specific type of lens known as toric lenses must be used. I have used screen shots to develop this tutorial as my previous tutorial shows how to bring in the dataset into Orange and extend it to the Data table and bring widgets into the scheme in Orange. This is on similar lines but however uses the Polyviz widget under the Visualize category. The first picture is the of dataset used generated by the Data Table widget. It shows how the data is categorized (the picture shows only the first few lines of the data set and is followed on similar lines).

 

The second picture shows all my widgets used in the scheme of this project. The scatterplot, and distributions are only used for inference, however the polyviz widget can be built without any of these widgets as well.

 

Once I give the data signal as input to the Polyviz widget, it allows us to visualize the data in many interesting ways. It assigns characteristics to each side of a polygon and automatically creates a scale and plots the data points. As shown in the picture below age, astigmatism and tear rate are the attributes compared with the type of lens color coded for easy comprehension. Various combinations such as *young and not astigmatic*   *myope and who is in the age bar pre-presbyopic* and so on can be analyzed with respect to lenses. The data points can be accesed by clicking on them and from the polyviz widget they can visualized as per the format we would like to subject to availability on the Orange widget tab.

Various combinations can be visualized by adding and removing the different parameters in the dialog box on the right hand side of the polyviz window. Polygons of any different sides can be developed by adding or removing parameters.

The intuitions gained form the Polyviz widget can be tested using various other widgets in Orange. Interesting correlations can be made with the given data set using the Polyviz widget.