Plotting 2-1/2 D Figures for General Type-2 Fuzzy Sets by Hand or by PowerPoint

Type-2 fuzzy logic systems that use general type-2 fuzzy sets (GT2 FSs) are now receiving renewed attention; hence, it is important to be able to communicate effectively about such fuzzy sets. While it is possible to generate the 3D membership functions (MFs) for these fuzzy sets using computer programs, this is not very useful for real-time on-the-fly discussions. Additionally, for most of us it is very difficult, if not impossible, to sketch or plot 3D MFs by hand. This short educational paper provides detailed instructions on how to plot different kinds of so-called 2 1/2 D plots for a GT2 FS. Using such 2 1/2 D plots should greatly enhance the communication about GT2 FSs and will therefore make them more accessible to the fuzzy logic community.