!______________________________________________________________________________
! 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) :: DELTA
  REAL, DIMENSION(N,2) :: X,Y,Z
  
  X(:,1)=REAL((/(i,i=1,N)/))/N
  X(:,2)=X(:,1)
  Y=X**2
  CALL RANDOM_NUMBER(DELTA)
  DELTA=(DELTA-0.5)/5
  Y(:,2)=Y(:,2)+DELTA
  
  ! This is an example of using Plot2D plot:
  CALL InitGraphics("2Dmatrix_test_plot.png","PNG",(/"Example of 2D plot","y=x^2"/),"x","y=x^2")
  CALL Plot2DMatrix(X,Y,"LS","|T","BR")
  CALL AddLegend((/"Fitted curve","Experimental points"/))
  CALL EndGraphics()

  Z=SQRT(X)
  Z(:,2)=Z(:,2)+DELTA
  
  ! This is an example of using Plot3D:
  CALL InitGraphics("3Dmatrix_test_plot.png","PNG",(/"Example of 3D plot","","<x,y,z>=<x,x^2$,x^0.5$>"/),"x","y=x^2","z=sqrt(x)")
  CALL Plot3DMatrix(X,Y,Z,"LS","|T","BR")
  CALL AddLegend((/"Fitted curve","Experimental points"/))
  CALL EndGraphics()  
  
END PROGRAM DISLIN_test