cpp_near_equal¶

C++ Check That Values are Nearly Equal¶

Prototype¶

namespace cmpad {
   template <class Type> bool near_equal(
      const Type&                x                                           ,
      const Type&                y                                           ,
      const Type                 rel_error                                   ,
      const cmpad::vector<Type>& vec       = cmpad::vector<Type>(0)          ,
      std::ostream&              os        = std::cerr                       )

Nearly Equal¶

Checks if two values are nearly equal; i.e., if

   std::fabs(x - y) <= abs_error

where the absolute error abs_error is defined below.

Type¶

is the type of the operands we are checking.

x¶

is the left operand in the nearly equal check.

y¶

is the right operand in the nearly equal check.

rel_error¶

is the relative error used during the comparison.

vec¶

This vector specifies extra values to include when scaling the relative error.

os¶

If the values are not nearly equal, a messages is written to this stream describing the comparison failure.

abs_error¶

scale is the maximum of the absolute value of x, y , and the elements of vec
tiny is the minimum positive normalized value of type Scalar
abs_error is maximum of tiny and rel_error times scale .

xam_near_equal.cpp contains an example and test of this routine.