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From: Matthias Teege <matthias@mteege.de>
Newsgroups: comp.lang.ada
Subject: exponentiation of fixed point or decimal
Date: 14 Dec 2000 19:24:53 +0100
Organization: DVZ Datenverarbeitungszentrum Mecklenburg-Vorpommern GmbH
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Date: 2000-12-14T19:24:53+01:00
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Moin,

I have a question about exponentiation of fixed point typs. The
following code didnt compile because of the '**' operator is not
defined for fixed point typs. So I made a lot of type conversions from
my fixed point type to float but the result for an Var_B of 10000
differs 0.01 of what my desk calculator says.

I have also made test with the numerics packages. If I use reals there
will be a better result but my "application" is for financial
transactions and I think fixed point or decimal is the best choice.

Is there any way for an exponentiation of fixed types?
 
procedure test is

   Max_Delta  : constant := 0.001;
   Max_Digits : constant := 15;

   type MyDec is delta Max_Delta digits Max_Digits;

   package MyDec_IO is new Ada.Text_IO.Decimal_IO(MyDec);

   Var_A: MyDec := 5.00;
   Var_B: MyDec;

   function myfunc(K: MyDec; Z: MyDec; Count: Positive ) return MyDec is
   begin
      return K * (1.00 + Z / 100) ** Count;
   -- return MyDec(Float(K) * Float((1.00 + Z / 100)) ** Count);
   end myfunc;

Begin
   MyDec_IO.Get(Var_B);
   MyDec_IO.Put(myfunc(Var_B, 5.00, 5), EXP=>0, FORE=>2, AFT=>2);
end test;

Many thanks
Matthias

-- 
Matthias Teege -- matthias@mteege.de -- http://emugs.de
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