Procedures for approximating dependences of several variables in MS Excel and Mathcad software environment

The article suggests a technique for approximating the original data via continuous smooth functions of several variables when performing the experimental part of a scientific study. The material is based on using such relatively common software like MS Excel and Mathcad, it can be implemented in structurally and functionally similar computer programs, and also provides results of practical application on the example of approximating the characteristics of a modern automobile internal combustion engine via functions of several variables of different kinds. In addition, the paper presents recommendations for rational use of the suggested methods and possible related difficulties in their implementation in the considered software shells. Theoretical material and practical examples of the approximation procedures prepared by the authors aredistinguished by a lot of options, flexibility of application to different types of representation of the original data, as well as the relative ease of use, because they are based on a simple-to-complex basis.