program gnufor_prb
!
!*******************************************************************************
!
!! GNUFOR_PRB tests the GNUFOR routines.
!
  implicit none
!
  call timestamp ( )

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'GNUFOR_PRB'
  write ( *, '(a)' ) '  A set of tests for GNUFOR.'

  call test01
  call test02
  call test03
  call test04
  call test05
  call test06

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'GNUFOR_PRB'
  write ( *, '(a)' ) '  Normal end of GNUFOR tests.'

  stop
end 
subroutine test01
!
!*******************************************************************************
!
!! TEST01 demonstrates the plotting of Y(X) data.
!
  implicit none
!
  integer, parameter :: n = 101
!
  real angle
  real area
  character ( len = 100 ) :: command_file_name = 'test01_commands.txt'
  character ( len = 100 ) :: data_file_name = 'test01_data.txt'
  integer i
  integer ierror
  real x(n)
  real, parameter :: xmin = 0.0+00
  real, parameter :: xmax = 20.0E+00
  real y(n)
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST01'
  write ( *, '(a)' ) '  To plot a simple set of (X,Y) data,'
  write ( *, '(a)' ) '  WRITE_XY_DATA writes the data file,'
  write ( *, '(a)' ) '  WRITE_XY_PLOT writes the plot command file.'

  do i = 1, n
    x(i) = ( real ( n - i ) * xmin + real ( i - 1 ) * xmax ) / real ( n - 1 )
    y(i) = sin ( x(i) ) * sin ( 4.0 * x(i) )
  end do

  call write_xy_data ( data_file_name, n, x, y, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST01'
    write ( *, '(a,i6)' ) '  WRITE_XY_DATA returned IERROR = ', ierror
  end if

  call write_xy_plot ( command_file_name, data_file_name, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST01'
    write ( *, '(a,i6)' ) '  WRITE_XY_PLOT returned IERROR = ', ierror
  end if

  call run_gnuplot ( command_file_name )

  return
end
subroutine test02
!
!*******************************************************************************
!
!! TEST02 demonstrates the plotting of a table of data.
!
  implicit none
!
  integer, parameter :: nrow = 101
  integer, parameter :: ncol = 4
!
  integer, parameter :: lda = nrow
!
  real angle
  real area
  character ( len = 100 ) :: command_file_name = 'test02_commands.txt'
  character ( len = 100 ) :: data_file_name = 'test02_data.txt'
  real height
  integer i
  integer ierror
  real, parameter :: r = 50.0E+00
  real width
  real x(lda,ncol)
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST02'
  write ( *, '(a)' ) '  To plot X versus multiple sets of Y data,'
  write ( *, '(a)' ) '  WRITE_XYY_DATA writes the data file,'
  write ( *, '(a)' ) '  WRITE_XYY_PLOT writes the plot command file.'

  do i = 1, nrow

    height = 2.0E+00 * r * real ( i - 1 ) / real ( nrow - 1 )
    width = 2.0E+00 * sqrt ( r**2 - ( r - height )**2 )
    angle = acos ( ( r - height ) / r )
    area = 0.5E+00 * r**2 * 2.0E+00 * acos ( ( r - height ) / r ) &
      - ( r - height ) * sqrt ( height * ( 2.0E+00 * r - height ) )

    x(i,1) = height
    x(i,2) = width
    x(i,3) = angle
    x(i,4) = area

  end do

  call write_xyy_data ( data_file_name, lda, nrow, ncol, x, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST02'
    write ( *, '(a,i6)' ) '  WRITE_XYY_DATA returned IERROR = ', ierror
  end if

  call write_xyy_plots ( command_file_name, data_file_name, ncol, &
    ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST02'
    write ( *, '(a,i6)' ) '  WRITE_XYY_PLOTS returned IERROR = ', ierror
  end if

  call run_gnuplot ( command_file_name )

  return
end
subroutine test03
!
!*******************************************************************************
!
!! TEST03 plots parameter (X,Y,Z) data.
!
  implicit none
!
  integer, parameter :: n = 101
!
  character ( len = 100 ) :: command_file_name = 'test03_commands.txt'
  character ( len = 100 ) :: data_file_name = 'test03_data.txt'
  integer i
  integer ierror
  integer, parameter :: nturn = 5
  real pi
  real, parameter :: r = 5.0E+00
  real theta
  real x(n)
  real y(n)
  real z(n)
  real, parameter :: zmax = 10.0E+00
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST03'
  write ( *, '(a)' ) '  To plot a (parametric) set of (X,Y,Z) data,'
  write ( *, '(a)' ) '  WRITE_XYZ_DATA writes the data file,'
  write ( *, '(a)' ) '  WRITE_XYZ_PLOT writes the plot command file.'

  do i = 1, n

    z(i) = zmax * real ( i - 1 ) / real ( n - 1 )

    theta = ( 2.0E+00 * pi() ) * z(i) * real ( nturn ) / zmax

    x(i) = r * cos ( theta )
    y(i) = r * sin ( theta )

  end do

  call write_xyz_data ( data_file_name, n, x, y, z, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST03'
    write ( *, '(a,i6)' ) '  WRITE_XYZ_DATA returned IERROR = ', ierror
  end if

  call write_xyz_plot ( command_file_name, data_file_name, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST03'
    write ( *, '(a,i6)' ) '  WRITE_XYZ_PLOT returned IERROR = ', ierror
  end if

  call run_gnuplot ( command_file_name )

  return
end
subroutine test04
!
!*******************************************************************************
!
!! TEST04 plots vector data.
!
  implicit none
!
  integer, parameter :: nx = 21
  integer, parameter :: ny = 21
  integer, parameter :: n = nx * ny
!
  character ( len = 100 ) :: command_file_name = 'test04_commands.txt'
  character ( len = 100 ) :: data_file_name = 'test04_data.txt'
  real dx(n)
  real dy(n)
  integer i
  integer ierror
  integer j
  integer k
  real x(n)
  real, parameter :: xmax = 1.0E+00
  real, parameter :: xmin = -1.0E+00
  real xx
  real y(n)
  real, parameter :: ymax = 1.0E+00
  real, parameter :: ymin = -1.0E+00
  real yy
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST04'
  write ( *, '(a)' ) '  To plot a vector field,'
  write ( *, '(a)' ) '  WRITE_VECTOR_DATA writes the data file,'
  write ( *, '(a)' ) '  WRITE_VECTOR_PLOT writes the plot command file.'

  k = 0

  do i = 1, nx
 
    do j = 1, ny

      k = k + 1

      xx = ( real ( nx - i ) * xmin + real ( i - 1 ) * xmax ) / real ( nx - 1 )
      yy = ( real ( ny - j ) * ymin + real ( j - 1 ) * ymax ) / real ( ny - 1 )

      dx(k) = - 0.10E+00 * yy
      dy(k) =   0.10E+00 * xx

      x(k) = xx - 0.5E+00 * dx(k)
      y(k) = yy - 0.5E+00 * dy(k)

    end do

  end do

  call write_vector_data ( data_file_name, n, x, y, dx, dy, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST04'
    write ( *, '(a,i6)' ) '  WRITE_VECTOR_DATA returned IERROR = ', ierror
  end if

  call write_vector_plot ( command_file_name, data_file_name, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST04'
    write ( *, '(a,i6)' ) '  WRITE_VECTOR_PLOT returned IERROR = ', ierror
  end if

  call run_gnuplot ( command_file_name )

  return
end
subroutine test05
!
!*******************************************************************************
!
!! TEST05 plots Z(X,Y) grid data as a surface.
!
  implicit none
!
  integer, parameter :: nx = 21
  integer, parameter :: ny = 21

  integer, parameter :: nrow = nx * ny
!
  character ( len = 100 ) :: command_file_name = 'test05_commands.txt'
  character ( len = 100 ) :: data_file_name = 'test05_data.txt'
  integer i
  integer ierror
  integer j
  real x
  real, parameter :: xmax = 1.0E+00
  real, parameter :: xmin = 0.0E+00
  real xyz(3,nx,ny)
  real y
  real, parameter :: ymax = 1.0E+00
  real, parameter :: ymin = 0.0E+00
  real z
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST05'
  write ( *, '(a)' ) '  To plot a gridded set of Z(X,Y) data as a surface,'
  write ( *, '(a)' ) '  WRITE_XYZGRID_DATA writes the data file,'
  write ( *, '(a)' ) '  WRITE_XYZGRID_SURFACE writes the plot command file.'

  do i = 1, nx

    x = ( real ( nx - i ) * xmin + real ( i - 1 ) * xmax ) / real ( nx - 1 )

    do j = 1, ny

      y = ( real ( ny - j ) * ymin + real ( j - 1 ) * ymax ) / real ( ny - 1 )

      z = sin ( 64.0E+00 * ( x - 0.5E+00 )**2 * ( y - 0.5E+00 )**2 )

      xyz(1,i,j) = x
      xyz(2,i,j) = y
      xyz(3,i,j) = z

    end do

  end do

  call write_xyzgrid_data ( data_file_name, nx, ny, xyz, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST05'
    write ( *, '(a,i6)' ) '  WRITE_XYZGRID_DATA returned IERROR = ', ierror
  end if

  call write_xyzgrid_surface ( command_file_name, data_file_name, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST05'
    write ( *, '(a,i6)' ) '  WRITE_XYZGRID_SURFACE returned IERROR = ', ierror
  end if

  call run_gnuplot ( command_file_name )

  return
end
subroutine test06
!
!*******************************************************************************
!
!! TEST06 plots Z(X,Y) grid data as contours.
!
  implicit none
!
  integer, parameter :: nx = 41
  integer, parameter :: ny = 41
!
  character ( len = 100 ) :: command_file_name = 'test06_commands.txt'
  character ( len = 100 ) :: data_file_name = 'test06_data.txt'
  integer i
  integer ierror
  integer j
  real x
  real, parameter :: xmax = 1.0E+00
  real, parameter :: xmin = 0.0E+00
  real xyz(3,nx,ny)
  real y
  real, parameter :: ymax = 1.0E+00
  real, parameter :: ymin = 0.0E+00
  real z
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'TEST06'
  write ( *, '(a)' ) '  To plot gridded Z(X,Y) data as contours,'
  write ( *, '(a)' ) '  WRITE_XYZGRID_DATA writes the data file,'
  write ( *, '(a)' ) '  WRITE_XYZGRID_CONTOUR writes the plot command file.'

  do i = 1, nx

    x = ( real ( nx - i ) * xmin + real ( i - 1 ) * xmax ) / real ( nx - 1 )

    do j = 1, ny

      y = ( real ( ny - j ) * ymin + real ( j - 1 ) * ymax ) / real ( ny - 1 )

      z = sin ( 64.0E+00 * ( x - 0.5E+00 )**2 * ( y - 0.5E+00 )**2 )

      xyz(1,i,j) = x
      xyz(2,i,j) = y
      xyz(3,i,j) = z

    end do

  end do

  call write_xyzgrid_data ( data_file_name, nx, ny, xyz, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST06'
    write ( *, '(a,i6)' ) '  WRITE_XYZGRID_DATA returned IERROR = ', ierror
  end if

  call write_xyzgrid_contour ( command_file_name, data_file_name, ierror )

  if ( ierror /= 0 ) then
    write ( *, '(a)' ) ' '
    write ( *, '(a)' ) 'TEST06'
    write ( *, '(a,i6)' ) '  WRITE_XYZGRID_CONTOUR returned IERROR = ', ierror
  end if

  call run_gnuplot ( command_file_name )

  return
end