with text_io,integer_io;                 use text_io,integer_io;
with Standard_Floating_Numbers;          use Standard_Floating_Numbers;
with Standard_Floating_Numbers_io;       use Standard_Floating_Numbers_io;
with Standard_Complex_Numbers;           use Standard_Complex_Numbers;
with Standard_Complex_Numbers_io;        use Standard_Complex_Numbers_io;
with Standard_Complex_Vectors;           use Standard_Complex_Vectors;
with Standard_Random_Vectors;            use Standard_Random_Vectors;
with Durand_Kerner;

procedure ts_durker is

-- DESCRIPTION :
--   Test on the solver for polynomial equations in one variable.

  procedure Read ( cv : in out Vector ) is
  begin
    for i in cv'range loop
      put(' '); put(i,1); put(" : ");
      get(cv(i));
    end loop;
  end Read;

  procedure Write ( step : in natural; z,res : in Vector ) is
  begin
    put("Output after step  "); put(step,1); put_line(" :");
    put_line
   ("------------------------------------------------------------------------");
    put_line
   ("|    APPROXIMATED ROOTS                        |     RESIDUALS         |");
    put_line
   ("------------------------------------------------------------------------");
    for i in z'range loop
      put("| "); put(z(i)); put(" | "); put(AbsVal(res(i))); put(" |");
      new_line;
    end loop;
    put_line
   ("------------------------------------------------------------------------");
  end Write;

  procedure dk is new Durand_Kerner(Write);

  procedure Main is

    n,nb : natural;

  begin
    put("Give the degree of p(x) : "); get(n);
    declare
      p : Vector(0..n);
      z,res : Vector(1..n);
      max : natural;
      eps : double_float;
    begin
      put_line("p(x) = a_0 + a_1*x + a_2*x^2 + ... + a_n*x^n");
      put("Give "); put(n+1,1); put_line(" complex coefficients of p(x) :");
      Read(p);
      z := Random_Vector(n);    -- first approximation is random vector
      res := z;
      put("Give the maximum number of steps : "); get(max);
      put("Give the required accuracy       : "); get(eps);
      dk(p,z,res,max,eps,nb);
    end;
  end Main;

begin
  Main;
end ts_durker;