Difference between revisions of "Talk:Not a Number"
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'''--[[User:Manus|manus]] 19:37, 8 May 2007 (CEST)''': Have a look at [[Real_numbers| Real Numbers]] page where we already started a similar discussion but currently only for the specification of REAL_64, not its usage. | '''--[[User:Manus|manus]] 19:37, 8 May 2007 (CEST)''': Have a look at [[Real_numbers| Real Numbers]] page where we already started a similar discussion but currently only for the specification of REAL_64, not its usage. | ||
| + | |||
| + | == One possibility for working with NaN == | ||
| + | |||
| + | I was working on a project to represent complex numbers and used the following `is_equal' to accomodate the use of NaNs: | ||
| + | |||
| + | |||
| + | is_equal (other: like Current): BOOLEAN | ||
| + | -- Is `other' attached to an object considered | ||
| + | -- equal to current object? | ||
| + | -- If current object is not a number (NaN) and | ||
| + | -- `other' is as well `True' will be returned. | ||
| + | do | ||
| + | if is_nan then | ||
| + | if real /~ real and then imaginary ~ imaginary then | ||
| + | Result := real /~ other.real and then imaginary ~ other.imaginary | ||
| + | elseif real ~ real and then imaginary /~ imaginary then | ||
| + | Result := real ~ other.real and then imaginary /~ other.imaginary | ||
| + | elseif real /~ real and then imaginary /~ imaginary then | ||
| + | Result := real /~ other.real and then imaginary /~ other.imaginary | ||
| + | end | ||
| + | else | ||
| + | Result := real ~ other.real and then imaginary ~ other.imaginary | ||
| + | end | ||
| + | end | ||
Revision as of 18:18, 19 February 2010
--manus 19:37, 8 May 2007 (CEST): Have a look at Real Numbers page where we already started a similar discussion but currently only for the specification of REAL_64, not its usage.
One possibility for working with NaN
I was working on a project to represent complex numbers and used the following `is_equal' to accomodate the use of NaNs:
is_equal (other: like Current): BOOLEAN
-- Is `other' attached to an object considered
-- equal to current object?
-- If current object is not a number (NaN) and
-- `other' is as well `True' will be returned.
do
if is_nan then
if real /~ real and then imaginary ~ imaginary then
Result := real /~ other.real and then imaginary ~ other.imaginary
elseif real ~ real and then imaginary /~ imaginary then
Result := real ~ other.real and then imaginary /~ other.imaginary
elseif real /~ real and then imaginary /~ imaginary then
Result := real /~ other.real and then imaginary /~ other.imaginary
end
else
Result := real ~ other.real and then imaginary ~ other.imaginary
end
end
