-- time_psimeq.adb
with Ada.text_io; use Ada.text_io;
with Ada.Calendar; use Ada.Calendar;
with Ada.Command_Line;
use  Ada;
with real_arrays; use real_arrays;
with psimeq;
--with Random; use Random; -- Udrnrt
with Ada.Numerics.Float_random; use Ada.Numerics.Float_random;


procedure Time_Psimeq is
  N : Positive := 200; -- number of equations
  NP : Positive := 8;   -- number of processors
  Start_Time : Duration;
  Debug : boolean := true;
  S : Generator;
  Udrnrt : Real;

  procedure Check(A:Real_Matrix; X:Real_Vector; Y:Real_Vector) is
    Sum  : Real := 0.0;
    Maxe : Real := 0.0;
    Diff : Real;
    Tmp  : Real;
  begin
    for I in 1..N loop
      Tmp := 0.0;
      for J in 1..N loop
        Tmp := Tmp + A(I,J)*X(J);
      end loop;
      Tmp := Tmp - Y(I);
      diff := abs(Tmp);
      if diff>Maxe then
        Maxe := diff;
      end if;
      sum := sum + diff;
    end loop; -- while
    Put_Line("check N="&Integer'Image(N)&
             ", NP="&Integer'Image(NP)&
             ", maxerr:="&Real'Image(Maxe));
  end check;

begin
  Put_Line("time_psimeq.adb");
  if Command_Line.Argument_Count >= 1 then
    N := Positive'Value(Command_Line.Argument(1));
  end if;
  Put_Line("number of equations N="&Integer'Image(N));
  if Command_Line.Argument_Count >= 2 then
    NP := Positive'Value(Command_Line.Argument(2));
  end if;
  Put_Line("number of processors NP="&Integer'Image(NP));

  declare
    X : Real_Vector(1..N);
    Y : Real_Vector(1..N);
    A : Real_Matrix(1..N,1..N); -- A * X = Y
  begin
    for I in 1..N loop
      for J in 1..N loop
        Udrnrt := Real(Random(S));
        A(I,J) := Udrnrt;
      end loop;
      Udrnrt := Real(Random(S));
      Y(I) := Udrnrt;
    end loop;
    if Debug then -- just see a few random numbers
      for I in 1..5 loop
        for J in 1..5 loop
           Put_Line("A"&Integer'Image(I)&","&Integer'Image(J)&
                    ")="&Real'image(A(I,J)));
        end loop;
        Put_Line("Y("&Integer'Image(I)&Real'Image(Y(I)));
      end loop;
    end if;
    Start_Time := Calendar.Seconds(Calendar.Clock);
    X := psimeq(NP, A, Y);
    Put_Line("wall time="&
             Duration'Image(Calendar.Seconds(Calendar.Clock)-Start_Time)&
             " seconds, N="&Integer'Image(N)&
             ", processors="&Integer'Image(NP));
    if Debug then
      Check(A, X, Y);
    end if;
    Put_Line("End Time_Psimeq");
  end; -- declare
end Time_Psimeq;