-- File:        BracketedRoot.cdl
-- Created:     Tue May 14 14:10:21 1991
-- Author:      Laurent Painnot
--              <lpa@topsn3>
---Copyright:    Matra Datavision 1991, 1992




class BracketedRoot from math
     	---Purpose: This class implements the Brent method to find the root of a function
     	-- located within two bounds. No knowledge of the derivative is required.

uses Matrix from math, 
     Vector from math, 
     Function from math,
     OStream from Standard

raises NotDone

is

    Create(F: in out Function;
    	   Bound1, Bound2, Tolerance: Real;
	   NbIterations: Integer = 100; ZEPS : Real =1.0e-12)
	---Purpose:   
    	-- The Brent method is used to find the root of the function F between 
    	-- the bounds Bound1 and Bound2 on the function F.
    	-- If F(Bound1)*F(Bound2) >0 the Brent method fails.  
    	-- The tolerance required for the root is given by Tolerance.
    	-- The solution is found when :
    	--    abs(Xi - Xi-1) <= Tolerance;
    	-- The maximum number of iterations allowed is given by NbIterations.

    returns BracketedRoot;
    
    IsDone(me)
    	---Purpose: Returns true if the computations are successful, otherwise returns false.
    	---C++: inline
    returns Boolean
    is static;


    Root(me)
        ---Purpose: returns the value of the root.
        -- Exception NotDone is raised if the minimum was not found.
     	---C++: inline
    returns Real
    raises NotDone
    is static;
    
    
    Value(me)
        ---Purpose: returns the value of the function at the root.
        -- Exception NotDone is raised if the minimum was not found.
      	---C++: inline
    returns Real
    raises NotDone
    is static;
    
    NbIterations(me)
        ---Purpose: returns the number of iterations really done during the
        -- computation of the Root.
        -- Exception NotDone is raised if the minimum was not found.
    	---C++: inline

    returns Integer
    raises NotDone
    is static;
    

    Dump(me; o: in out OStream)
	---Purpose: Prints on the stream o information on the current state 
    	--          of the object.

    is static;



fields

Done:      Boolean;
TheRoot:   Real;
TheError:  Real;
NbIter:    Integer;

end BracketedRoot;