-- File:         DirectPolynomialRoots.cdl
-- Created:      Mon May 13 16:47:42 1991
-- Author:       Laurent PAINNOT
--               <lpa@topsn3>
---Copyright:     Matra Datavision 1991, 1992


class DirectPolynomialRoots from math
    	---Purpose:
    	-- This class implements the calculation of all the real roots of a real 
    	-- polynomial of degree <= 4 using a direct method. Once found, 
    	-- the roots are polished using the Newton method.

uses OStream from Standard

raises RangeError from Standard,
       InfiniteSolutions from StdFail

is
    Create(A, B, C, D, E: Real)
    	---Purpose:
        -- computes all the real roots of the polynomial 
        -- Ax4 + Bx3 + Cx2 + Dx + E using a direct method.
    returns DirectPolynomialRoots;

    
    
    Create(A, B, C, D: Real)
    	---Purpose:
        -- computes all the real roots of the polynomial 
        -- Ax3 + Bx2 + Cx + D using a direct method.

    returns DirectPolynomialRoots;
    
    
    
    Create(A, B, C: Real)
    	---Purpose:
        -- computes all the real roots of the polynomial 
        -- Ax2 + Bx + C using a direct method.

    returns DirectPolynomialRoots;
    
    
    Create(A, B: Real)
    	---Purpose:
        -- computes the real root of the polynomial Ax + B.

    returns DirectPolynomialRoots;
    

    Solve(me: in out; A, B, C, D, E: Real)
    is static protected;

    Solve(me: in out; A, B, C, D: Real)
    is static protected;

    Solve(me: in out; A, B, C: Real)
    is static protected;
    
    Solve(me: in out; A, B: Real)
    is static protected;

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

    InfiniteRoots(me)
	---Purpose: Returns true if there is an infinity of roots, otherwise returns false.
    	---C++: inline
    returns Boolean
    is static;


    NbSolutions(me)
    	---Purpose: returns the number of solutions.
    	--          An exception is raised if there are an infinity of roots.
    	---C++: inline
    returns Integer
    raises InfiniteSolutions
    is static;
    
    
    Value(me; Nieme: Integer)
    	---Purpose: returns the value of the Nieme root.
    	--          An exception is raised if there are an infinity of roots.
        --          Exception RangeError is raised if Nieme is < 1 
        --          or Nieme > NbSolutions.
    	---C++: inline

    returns Real
    raises InfiniteSolutions, RangeError
    is static;
    
    Dump(me; o: in out OStream)
	---Purpose: Prints on the stream o information on the current state 
    	--          of the object.
    	--          Is used to redefine the operator <<.

    is static;


fields

Done:                Boolean;
InfiniteStatus:      Boolean;
NbSol:     Integer;
TheRoots:  Real[4];

end DirectPolynomialRoots;