Nonsensical Excel and Statistica Default Output and Algorithm for an Adequate Display

Abstract

The purpose of this paper is to present an algorithm that determines the necessary and sufficient number of significant digits in the coefficients of polynomial trend in order to achieve a pre-specified precision of polynomial trend. Thus, the obtained coefficients should be presented in the default output when fitting the experimental data by polynomial trend. Namely, in order to find the best fitting function for certain type of data there is a real possibility of making significant errors using default output of Excel 2003Excel , 2007Excel , 2010Excel , 2013 and Statistica for Windows 2007-2012 software packages. Conversely, software package Mathematica (version 6) has shown very good characteristics in dealing with precision problems, although the default output sometimes shows more significant digits than necessary. Also, it turned out that the software packages Excel and Statistica violated the order of operations as defined in mathematics. For example, −1 2 = 1 and −(−3) 2 = 9. This problem always occurs in Excel, while at Statistica during the graphical interpretation of a function.