Abstract
At the beginning of the chapter, the desktop of the software, its toolbars, and main windows are introduced. Examples of interactive calculations with MATLAB® language are presented. Elementary functions, input and output commands, numbers and strings, vectors, matrices and arrays, flow control commands, relational and logical operators are discussed. Each command is presented in its most applicable form and with practical examples. At the end of each subsection, the commands studied are applied to elementary problems in the field of mechanical and tribological (M&T) sciences and technology, in particular to such as stress intensity factor, stiffness of a threaded bolt, adhesive force in contact between two spheres, and many others.
Top2.1. Running The Matlab® Software
The user must install MATLAB® before working with him. Therefore, it is assumed that this software was previously installed on your computer. MATLAB®, like other computer software, is controlled by a special set of programs called the operating system (OS), which may differ according to the computing platforms. Therefore, we additionally assume here, that MATLAB® is controlled by the OS Windows. To open MATLAB®, click the icon 
showing a red L-shaped membrane. This icon should previously be placed in the Windows Start Menu, the Desktop and on Task bar. Another way to start MATLAB® is to type the word MATLAB® in the Windows Search box. You can also start the program by finding and clicking the matlab.exe file in the MATLAB® bin directory. The path to this file might look like this C:\Program Files\MATLAB\R2019b\bin\matlab.exe. After that, a startup picture appears with the MATLAB® logo and some product information, including the initial version, license number and the name of the development company. This image disappears after a short time after which the MATLAB® desktop opens.