Abstract:

The principal motivation for this work is to help better understanding of Lognormal random variable, by visualizing its characteristics and demonstrating its relation with Normal random variable.

To this end, we create a Demo program in MATLAB for teaching characteristics of Lognormal random variable.

As it is well known MATLAB is now the tool of choice for research and educational purpose. From the other side, demo programs are important complementary tool in teaching and learning process, in many engineering subjects. However, the advantage of our approach is that the student does not need MATLAB or any other programming language experience and may direct their full attention to the presented subject. Additionally, to fulfill the active participation of students, the demos are interactive and the students are asked to choose the corresponding parameters.

Our experience shows that teaching in a traditional way a primer course on random variable and processes is a little bit abstract and difficult for students. In order to increase teaching efficiency and help in better understanding, we created various demo programs for teaching random variables, as a complement to the traditional classes in the classroom. Recently, during COVID pandemic, such demo programs were very useful for better understanding different aspects of random variables, during online classes.

This Demo program is dedicated to Lognormal random variable, important in communication systems, and reliability among others.
The Demo program consists of 6 demonstrations.

The goal of First demonstration is to show the relation of Lognormal random variable and Normal Random Variable.

Second demonstration shows the generation of Lognormal random variable from the corresponding Normal random variable.

In Third demonstration is presented estimation of Probability Density Function (PDF) and Distribution, using histogram.

The relation of the shape of PDF of lognormal random variable, and parameters of the corresponding Normal random variable, is shown in Fourth demonstration.

The purpose of Fifth demonstration is to present the behavior of the sum of independent Lognormal random variables.

Finally, Sixth demonstration presents the behavior of the product of independent Lognormal random variables.

Keywords:

Demo program, random variables, Lognormal random variable, Normal random variable, PDF, Distribution, transformation.