!___________________________________________________________________________________________________
! Aleksandar Donev
! PHY201 Solutions to Worksheet
! December, 2000, MSU
!___________________________________________________________________________________________________
!
PROGRAM Erf_Plot
   USE Precision
   USE Erf_Series, ONLY: error
   USE Erf_Timing
   USE SimpleGraphics
   USE FunGraphics
   
   IMPLICIT NONE   

   ! We are in position to choose whether we want REAL or COMPLEX x:
   ! Comment one of these out:
   INTEGER :: i,k,status,n_points ! I/O status
	REAL(KIND=sp), PARAMETER :: x_min=0.0,x_max=4.5 ! Range of plot
   CHARACTER(50), DIMENSION(2) :: title
   CHARACTER(3), DIMENSION(2) :: spec
  
   UserInput: DO 
     WRITE(UNIT=*,FMT="(A)",ADVANCE="NO") "Enter: n_points and error: "
     READ(UNIT=*,FMT=*,IOSTAT=status) n_points,error
     IF(status==0) EXIT UserInput ! Do not exit until the user enters acceptable numbers
   END DO UserInput  

   title(1)="Timing benchmark for the function ErfSeries(x)"
   WRITE(title(2),*) "epsilon=",error,", A. Donev 1/10/00"
   ! We plot the curve both with points and with symbols:  
   spec(1)="L-B" ! Line
   spec(2)="STR" ! Symbols
   CALL InitGraphics(file="Erf_Timing.PNG",file_type="CONS", &
                    plot_title=title, &
                    x_label="x",y_label="time (us)")            	   
   CALL FunPlot2D(f_x=TimeErf,x_range=(/x_min,x_max/),num_points=n_points, &
                  plot_spec=spec)   
   CALL EndGraphics()

END PROGRAM Erf_Plot
!