## 2 Materials and Methods
### IVEE Functionality  
This section demonstrates how IVEE can assist in the generation of interactive visualizations in the immersive space. We illustrate the use of IVEE through a pilot study to further investigate the feasibility of using this engine and to evaluate the system's functionality and performance in relation to data retrieval, user interfacing, and graphical rendering performance. Analyzing multidimensional/multivariate data on 2D interfaces requires a variety of summary visualizations and reports that must be brought together to inform decision-making. These techniques have their disadvantages; complex interrelationships are hard to spot, and analysts cannot discern a modern dataset relying on 2D interfaces without the possibility of eliminating important details. Additionally, 2D graphics only provide one part of a more complex structure, and it is arduous to find meaningful information when one cannot visualize datasets as they are. Clearly, the field of analytics requires the means to visualize multivariate datasets as they are. VR immersive mediums offer various advantages for multivariate/multidimensional data, including greater space and the third dimension. Hence, they provide a much better way of reviewing and examining modern datasets. IVEE can visualize multivariate datasets, and enables users to manipulate them inside the virtual space without programming. In the following sections, we show how the IVEE engine works and demonstrate how to use its data sub-setting and merging features currently available in this engine version. First, we demonstrate the gesture-based central menu system. The idea was to tie all the options to only two buttons on the right-hand Oculus Touch controller to reduce the users' cognitive load (Figure 3). Consequently, users do not have to remember any complicated button combinations but only press the button and swipe to select (Figure 4). When a user is placed inside the virtual space of IVEE by wearing the Oculus headset and holding the touch controllers with both real hands, he/she can see his/her virtual hands holding virtual controllers as if they were real (Figure 3). When the user moves his/her real hands that hold the real touch controllers, his/her virtual hands move accordingly in the  
another virtual object in the scene (Figure 7g). AES stands for aesthetics and helps to assign different data attributes to desired axes (Figure 7h). Depending on the type and dimension of visualization, users can assign attributes accordingly. For instance, if users are interested in visualizing a 3D scatterplot of the data, they can assign the desired attributes to three axes. On the other hand, if they wish to generate a 2D line plot, they can assign two data attributes to the x and y axis, leaving the third axis empty. Before assigning any attributes, users should create a connection between the two generated virtual objects by holding them with virtual hands and bringing them into contact. The contact between the two objects is marked by a red band (Figure 7). Combining the two objects feeds the \"AES\"-generated virtual objects with chosen data attributes, allowing users to make their selection. Users then press the A button and swipe to the \"Plot Type\" element, bringing up another nested menu that holds the plot types (Figure 7j). Figure 7: The successive steps leading to the generation of a visualization in IVEE. (**a**) IVEE’s menu system. (**b**) Selecting a database by touch. (**c**) Showing all files in the database. (**d**) Selecting a file by touch. (**e**) Virtual object represents the selected file. (**f**) IVEE’s sub menu system. (**g**) AES element. (**h**) Assigning different data attributes to desired axes. (**i**) Selecting the desired plot type. (**j**) Virtual object represents the plot type. The combination of these virtual objects creates a set of arguments that are sent to R through a C# script.