Return to m_homogeneous_bezout_numbers.ads CVS log

Up to [local] / OpenXM_contrib / PHC / Ada / Root_Counts / Product

Import the second public release of PHCpack.

OKed by Jan Verschelde.

with Standard_Complex_Poly_Systems;      use Standard_Complex_Poly_Systems;
with Partitions_of_Sets_Of_Unknowns;     use Partitions_of_Sets_of_Unknowns;

package m_Homogeneous_Bezout_Numbers is

-- DESCRIPTION :
--   This package allows the computation of m-homogeneous Bezout numbers.
--   It provides various enumeration strategies for computing a minimal
--   m-homogeneous Bezout number.

  function Total_Degree ( p : Poly_Sys ) return natural;

  -- DESCRIPTION :
  --   Returns the 1-homogeneous Bezout number of the system.

  function Bezout_Number ( p : Poly_Sys; z : Partition ) return natural;
  function Bezout_Number ( p : Poly_Sys; z : Partition; max : natural )
                         return natural;

  -- DESCRIPTION :
  --   Returns the m-homogeneous Bezout number w.r.t. the given partition.
  --   When max is given as parameter, the computation stops when the
  --   result becomes larger than or equal to max.

  function Bezout_Number ( p : Poly_Sys ) return natural;
  function Bezout_Number ( max : natural; p : Poly_Sys ) return natural;
  function Bezout_Number ( p : Poly_Sys; min : natural ) return natural;
  function Bezout_Number ( max : natural; p : Poly_Sys; min : natural )
                         return natural;
  -- DESCRIPTION :
  --   A minimal m-homogeneous Bezout number of the polynomial system 
  --   p is computed, by generating partitions of the sets of unknowns.

  -- ON ENTRY :
  --   p         a polynomial system;
  --   max       a maximum number of partition to be evaluated,
  --             if max=0, then the total degree is returned;
  --   min       the procedure stops when the Bezout number becomes
  --             smaller than min.

  procedure Bezout_Number 
               ( p : in Poly_Sys; b,m : out natural; z : in out Partition );
  procedure Bezout_Number 
               ( max : in natural; p : in Poly_Sys; b,m : out natural;
                 z : in out Partition );
  procedure Bezout_Number
               ( p : in Poly_Sys; min : in natural; b,m : out natural;
                 z : in out Partition );
  procedure Bezout_Number
               ( max : in natural; p : in Poly_Sys; min : in natural;
                 b,m : out natural; z : in out Partition );

  -- DESCRIPTION :
  --   A minimal m-homogeneous Bezout number of the polynomial system
  --   is computed.  The partition with the calculated Bezout number
  --   is returned.

  -- ON ENTRY :
  --   p         a polynomial system;
  --   max       a maximum number of partition to be evaluated,
  --             if max=0, then the total degree is returned;
  --   min       the procedure stops when the Bezout number becomes
  --             smaller than min.

  -- ON RETURN :
  --   b         a minimal m-homogeneous Bezout number;
  --   m         the number of sets in the partition z;
  --   z         the partition with the computed Bezout number b.

  procedure PB ( p : in Poly_Sys; b,m : out natural; z : in out Partition );

  -- DESCRIPTION :
  --   This is a fast heuristic for computing `the' Bezout number of p.
  --   It is fast because it does not generate all partitions,
  --   it is a heuristic because it does not always give then
  --   minimal partition.

  -- ON ENTRY :
  --   p         a polynomial system.

  -- ON RETURN :
  --   b         an m-homogeneous Bezout number;
  --   m         the number of sets in the partition z;
  --   z         the partition corresponding to b.

end m_Homogeneous_Bezout_Numbers;