1. Special Functions

Note – This document was created using AI translation.

1.1 Overview

Programming language processors (such as compilers) provide basic functions for scientific and technical calculations. These are called standard functions and generally include square roots, exponential and logarithmic functions, trigonometric functions, and inverse trigonometric functions.

Although not strictly defined, functions that are slightly more complex than the basic ones mentioned above but are commonly used in engineering are called special functions. These are not provided by language processors but are typically included in numerical computation libraries and provided separately.

1.2 Special Functions Available in XLPack

XLPack provides worksheet functions and VBA functions such as Bessel functions, Airy functions, elliptic integrals, exponential and logarithmic integrals, gamma functions, beta functions, digamma functions, error functions, and hypergeometric functions. Many of these are based on the C++ Boost library (Math/Special Functions) and C99 standard functions.

In XLPack (basic functionality), the basic ones among these can be used.

Worksheet functions start with the letter W (W + VBA function name). Depending on the settings, you may be able to call VBA functions directly from the worksheet instead of worksheet functions starting with W, but please do not do this.

Example: The VBA function for logarithmic integral is Li, and the worksheet function is WLi.

1.3 Excel’s Special Functions

To avoid duplication with the worksheet functions standardly equipped in Excel, the following worksheet functions are not provided. Please use Excel’s worksheet functions.

Gamma functions: WGamma, WLngam -> GAMMA, GAMMALN, GAMMALN.PRECISE

Error functions: WErf, WErfc -> ERF, ERF.PRECISE, ERFC, ERFC.PRECISE

Bessel functions: WBesjn, WBesyn -> BESSELJ, BESSELY WBesin, WBeskn -> BESSEIJ, BESSEKY

Factorial: WFactorial -> FACT, FACTDOUBLE