1.3 Exceptional Arguments

Not all mathematical functions are capable of returning a meaningful result for all input argument values. Any argument value passed to a DPML routine that does not return a meaningful result, or is defined differently for different environments, is referred to as an exceptional argument. Exceptional arguments that result in an exception behavior are documented in the Exceptions section of each DPML routine in Chapter 2.

Exceptional arguments typically fall into one of two categories:

• Domain errors or invalid arguments. These are arguments for which a function is not defined. For example, the inverse sine function, asin, is defined only for arguments between -1 and +1 inclusive. Attempting to evaluate acos(-2) or acos(3) results in a domain error or invalid argument error.

• Range errors. These errors occur when a mathematically valid argument results in a function value that exceeds the range of representable values for the floating-point data type. Appendix A gives the approximate minimum and maximum values representable for each floating-point data type.