!______________________________________________________________________________
! This program demonstrates how to use the Graphics module to plot 2D curves
! It plots the function y=x^2 exactly and with random deviations.
! The function Plot3D is used identically, but with x,y and z data.
!______________________________________________________________________________
PROGRAM DISLIN_test
  USE Graphics
  
  IMPLICIT NONE
  INTEGER, PARAMETER :: N=10
  INTEGER :: i
  REAL, DIMENSION(N) :: X,Y,Z,DELTA,Y_,Z_
  INTEGER, EXTERNAL :: MyGraphics
  
  X=REAL((/(i,i=1,N)/))/N
  Y=X**2
  CALL RANDOM_NUMBER(DELTA)
  DELTA=(DELTA-0.5)/5
  Y_=Y+DELTA

  ! This is an example of using Plot2D plot:
  CALL InitGraphics("2D_test_plot.tif","TIFF",(/"Example of 2D plot"/),"x","y=x^2",my_func=MyGraphics)
  CALL Plot2D(X,Y,"L-R",X,Y_,"STB",X,Y_,"L|G",my_func=MyGraphics)
  CALL EndGraphics(my_func=MyGraphics)

  Z=SQRT(X)
  Z_=Z+DELTA
  
  ! This is an example of using Plot3D:
  CALL InitGraphics("3D_test_plot.tif","TIFF",(/"Example of 3D plot"/),"x","y=x^2","z=sqrt(x)",my_func=MyGraphics)
  CALL Plot3D(X,Y,Z,"L-R",X,Y_,Z_,"STB",X,Y_,Z_,"L|G",my_func=MyGraphics)
  CALL EndGraphics(my_func=MyGraphics)  
  
END PROGRAM DISLIN_test

!______________________________________________________________________________
! This subroutine is an example of what can be passed to 2DPlot
! to perform functions not in the routine, like making a legend
! and performing a spline fit to the data points:
!______________________________________________________________________________
INTEGER FUNCTION MyGraphics(level)
  USE DISLIN
  IMPLICIT NONE
  CHARACTER*60  Leg
  INTEGER :: level
  SELECT CASE(level)
    CASE(-1)
      CALL LEGCLR
      CALL LEGEND(Leg,3)
    CASE(0)
    CASE(1)
      CALL LEGINI(Leg,3,20)
      CALL LEGLIN(Leg,"Fitted parabola",1)
      CALL LEGLIN(Leg,"Experimental points",2) 
      CALL LEGLIN(Leg,"Fitted spline",3)           
    CASE(2)
      CALL POLCRV("SPLINE")
    CASE(3)
  END SELECT
  MyGraphics=1
END FUNCTION MyGraphics