DEFINITION MODULE DBrentM;

(* EXPORT QUALIFIED DBrent; *)

   FROM NRMath IMPORT RealFunction;

   PROCEDURE DBrent(    ax, bx, cx: REAL;
                        func, dfunc: RealFunction;
                        tol:         REAL; 
                    VAR xmin: REAL): REAL; 
   (*
     Given a function func and its derivative function dfunc, and given a 
     bracketing triplet of abscissas ax, bx, cx [such that bx is between ax
     and cx, and func(bx) is less than both func(ax) and func(cx)],
     this routine isolates the minimum to a fractional precision of about
     tol using a modification of Brent's method that uses derivatives.  
     The abscissa of the minimum is returned as xmin, and the minimum function
     value is the returned function value.
   *)

END DBrentM.