File: [local] / OpenXM_contrib / PHC / Ada / Math_Lib / Numbers / multprec_floating_numbers.ads (download)
Revision 1.1.1.1 (vendor branch), Sun Oct 29 17:45:26 2000 UTC (23 years, 9 months ago) by maekawa
Branch: PHC, MAIN
CVS Tags: v2, maekawa-ipv6, RELEASE_1_2_3, RELEASE_1_2_2_KNOPPIX_b, RELEASE_1_2_2_KNOPPIX, RELEASE_1_2_2, RELEASE_1_2_1, HEAD Changes since 1.1: +0 -0
lines
Import the second public release of PHCpack.
OKed by Jan Verschelde.
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with Multprec_Natural_Numbers; use Multprec_Natural_Numbers;
with Multprec_Integer_Numbers; use Multprec_Integer_Numbers;
with Standard_Floating_Numbers; use Standard_Floating_Numbers;
package Multprec_Floating_Numbers is
-- DESCRIPTION :
-- This package provides operations to deal with floating-point numbers
-- of arbitrary length. The size of the fraction remains fixed during
-- computations, but can be adjusted. The exponent has no fixed size.
-- Mixed-precision arithmetic is fully supported: the size of the result
-- in any binary operation is the maximal size of the operands.
type Floating_Number is private;
-- CONSTRUCTORS :
function Create ( i : integer ) return Floating_Number;
function Create ( i : Integer_Number ) return Floating_Number;
function Create ( f : double_float ) return Floating_Number;
function Create ( fraction,exponent : integer ) return Floating_Number;
function Create ( fraction : Integer_Number;
exponent : integer ) return Floating_Number;
function Create ( fraction : integer;
exponent : Integer_Number ) return Floating_Number;
function Create ( fraction,exponent : Integer_Number ) return Floating_Number;
-- DESCRIPTION :
-- A floating point number consists of a fraction and exponent.
-- SELECTORS :
function Fraction ( f : Floating_Number ) return Integer_Number;
function Exponent ( f : Floating_Number ) return Integer_Number;
-- DESCRIPTION :
-- Returns the fraction and the exponent. Warning: sharing!
-- We have that f = Fraction(f)*10**Exponent(f).
function Size_Fraction ( f : Floating_Number ) return natural;
function Size_Exponent ( f : Floating_Number ) return natural;
-- DESCRIPTION :
-- Returns the length of the coefficient vector of the representations
-- of fraction and exponent as integer numbers.
-- Size_Fraction(f) = 1 corresponds to the precision of the standard
-- double floating-point numbers.
function Decimal_Places_Fraction ( f : Floating_Number ) return natural;
function Decimal_Places_Exponent ( f : Floating_Number ) return natural;
-- DESCRIPTION :
-- Returns the number of decimal places in fraction and exponent.
function Decimal_to_Size ( deci : natural ) return natural;
-- DESCRIPTION :
-- Returns the smallest size to obtain the given number of decimal places.
-- This is useful for the "Set_Size" operation.
function AbsVal ( f : Floating_Number ) return Floating_Number;
-- DESCRIPTION :
-- Returns the absolute value of f.
-- COMPARISON AND COPYING :
function Equal ( f1 : Floating_Number; f2 : double_float ) return boolean;
function Equal ( f1,f2 : Floating_Number ) return boolean;
-- DESCRIPTION :
-- Returns true if f1 and f2 are equal, false otherwise.
function "<" ( f1 : double_float; f2 : Floating_Number ) return boolean;
function "<" ( f1 : Floating_Number; f2 : double_float ) return boolean;
function "<" ( f1,f2 : Floating_Number ) return boolean;
-- DESCRIPTION :
-- Returns true if f1 < f2, false otherwise.
function ">" ( f1 : double_float; f2 : Floating_Number ) return boolean;
function ">" ( f1 : Floating_Number; f2 : double_float ) return boolean;
function ">" ( f1,f2 : Floating_Number ) return boolean;
-- DESCRIPTION :
-- Returns true if f1 > f2, false otherwise;
procedure Copy ( f1 : in Floating_Number; f2 : in out Floating_Number );
-- DESCRIPTION :
-- Clears f2 and copies the content of f1 into f2.
-- Note that f2 := f1 leads to data sharing.
-- EXPANDING and SHORTENING THE MANTISSA :
function Expand ( f : Floating_Number; k : natural ) return Floating_Number;
procedure Expand ( f : in out Floating_Number; k : in natural );
-- DESCRIPTION :
-- Expands the fraction by adding k coefficients.
function Round ( f : Floating_Number ) return double_float;
function Round ( f : Floating_Number; k : natural ) return Floating_Number;
procedure Round ( f : in out Floating_Number; k : in natural );
function Trunc ( f : Floating_Number ) return double_float;
function Trunc ( f : Floating_Number; k : natural ) return Floating_Number;
procedure Trunc ( f : in out Floating_Number; k : in natural );
-- DESCIRPTION :
-- Shortens the fraction by removing k coefficients, either by rouding
-- or by truncation of the least significant coefficients.
procedure Set_Size ( f : in out Floating_Number; k : in natural );
-- DESCRIPTION :
-- Sets the size of the floating number f to k, either by rounding
-- or expanding its current size.
-- ARITHMETIC OPERATIONS as functions (no data sharing) :
-- The size of the result is the maximal size of the operands.
function "+" ( f1 : Floating_Number; f2 : double_float )
return Floating_Number;
function "+" ( f1 : double_float; f2 : Floating_Number )
return Floating_Number;
function "+" ( f1,f2 : Floating_Number ) return Floating_Number;
function "+" ( f : Floating_Number ) return Floating_Number; -- copy of f
function "-" ( f : Floating_Number ) return Floating_Number;
function "-" ( f1 : Floating_Number; f2 : double_float )
return Floating_Number;
function "-" ( f1 : double_float; f2 : Floating_Number )
return Floating_Number;
function "-" ( f1,f2 : Floating_Number ) return Floating_Number;
function "*" ( f1 : Floating_Number; f2 : double_float )
return Floating_Number;
function "*" ( f1 : double_float; f2 : Floating_Number )
return Floating_Number;
function "*" ( f1,f2 : Floating_Number ) return Floating_Number;
function "**" ( f : double_float; n : Natural_Number ) return Floating_Number;
function "**" ( f : Floating_Number; n : Natural_Number )
return Floating_Number;
function "**" ( f : Floating_Number; i : integer ) return Floating_Number;
function "**" ( f : double_float; i : Integer_Number ) return Floating_Number;
function "**" ( f : Floating_Number; i : Integer_Number )
return Floating_Number;
function "/" ( f1 : Floating_Number; f2 : double_float )
return Floating_Number;
function "/" ( f1 : double_float; f2 : Floating_Number )
return Floating_Number;
function "/" ( f1,f2 : Floating_Number ) return Floating_Number;
-- ARITHMETIC OPERATIONS as procedures for memory management :
procedure Add ( f1 : in out Floating_Number; f2 : in double_float ); -- "+"
procedure Add ( f1 : in out Floating_Number; f2 : in Floating_Number );
procedure Sub ( f1 : in out Floating_Number; f2 : in double_float ); -- "-"
procedure Sub ( f1 : in out Floating_Number; f2 : in Floating_Number );
procedure Min ( f : in out Floating_Number );
procedure Mul ( f1 : in out Floating_Number; f2 : in double_float ); -- "*"
procedure Mul ( f1 : in out Floating_Number; f2 : in Floating_Number );
procedure Div ( f1 : in out Floating_Number; f2 : in double_float ); -- "/"
procedure Div ( f1 : in out Floating_Number; f2 : in Floating_Number );
-- DESTRUCTOR :
procedure Clear ( f : in out Floating_Number );
-- DESCRIPTION :
-- Deallocations of the occupied memory for f.
private
type Floating_Number is record
fraction,exponent : Integer_Number;
end record;
end Multprec_Floating_Numbers;