lines 11-75 of file: cpp/include/cmpad/near_equal.hpp

{xrst_begin cpp_near_equal}
{xrst_spell
   fabs
   os
   rel
   std
   vec
}

C++ Check That Values are Nearly Equal
######################################

Prototype
*********
{xrst_literal
   // BEGIN PROTOTYPE
   // END PROTOTYPE
}

Nearly Equal
************
Checks if two values are nearly equal; i.e., if
{xrst_code cpp}
   std::fabs(x - y) <= abs_error
{xrst_code}
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* .

{xrst_toc_hidden
   cpp/xam/near_equal.cpp
}
:ref:`xam_near_equal.cpp-name` contains an example and test of this routine.

{xrst_end cpp_near_equal}