#!/usr/bin/env python
#
def tetrahedron_grid_display ( xv, ng, xg, filename ):

#*****************************************************************************80
#
## TETRAHEDRON_GRID_DISPLAY displays grid points inside a tetrahedron.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    15 April 2015
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, real XV[4,3], the vertices.
#
#    Input, integer NG, the number of grid points.
#
#    Input, real XG[NG,3], the grid points.
#
#    Input, string FILENAME, the name of the plotfile to be created.
#
  import matplotlib.pyplot as plt
  from mpl_toolkits.mplot3d import Axes3D

  fig = plt.figure ( )
  ax = fig.add_subplot ( 111, projection = '3d' )
#
#  Draw the grid points.
#
  ax.scatter ( xg[:,0], xg[:,1], xg[:,2], 'b' )
#
#  Outline the region by its edges.
#
  ax.plot ( [ xv[0,0], xv[1,0] ], [ xv[0,1], xv[1,1] ], [ xv[0,2], xv[1,2] ], 'r' )
  ax.plot ( [ xv[0,0], xv[2,0] ], [ xv[0,1], xv[2,1] ], [ xv[0,2], xv[2,2] ], 'r' )
  ax.plot ( [ xv[0,0], xv[3,0] ], [ xv[0,1], xv[3,1] ], [ xv[0,2], xv[3,2] ], 'r' )
  ax.plot ( [ xv[1,0], xv[2,0] ], [ xv[1,1], xv[2,1] ], [ xv[1,2], xv[2,2] ], 'r' )
  ax.plot ( [ xv[1,0], xv[3,0] ], [ xv[1,1], xv[3,1] ], [ xv[1,2], xv[3,2] ], 'r' )
  ax.plot ( [ xv[2,0], xv[3,0] ], [ xv[2,1], xv[3,1] ], [ xv[2,2], xv[3,2] ], 'r' )

  ax.set_xlabel ( '<---X--->' )
  ax.set_ylabel ( '<---Y--->' )
  ax.set_zlabel ( '<---Z--->' )
  ax.set_title ( 'Grid points in tetrahedron' )
  ax.grid ( True )
  ax.axis ( 'equal' )

  plt.savefig ( filename )
  plt.show ( )
  plt.clf ( )

  return

def tetrahedron_grid_display_test ( ):

#*****************************************************************************80
#
## TETRAHEDRON_GRID_DISPLAY displays grid points inside a tetrahedron.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    15 April 2015
#
#  Author:
#
#    John Burkardt
#
  import numpy as np
  import platform

  print ( '' )
  print ( 'TETRAHEDRON_GRID_DISPLAY_TEST:' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  TETRAHEDRON_GRID_DISPLAY can display a grid of points in a tetrahedron.' )

  xv = np.array ( [ \
    [ 0.0, 0.0, 0.0 ], \
    [ 2.0, 0.0, 0.0 ], \
    [ 0.0, 2.0, 0.0 ], \
    [ 0.0, 0.0, 2.0 ] ] )

  ng = 10
  xg = np.array ( [ \
    [  0.0,  0.0,  0.0 ], \
    [  1.0,  0.0,  0.0 ], \
    [  2.0,  0.0,  0.0 ], \
    [  0.0,  1.0,  0.0 ], \
    [  0.0,  2.0,  0.0 ], \
    [  1.0,  1.0,  0.0 ], \
    [  0.0,  0.0,  1.0 ], \
    [  1.0,  0.0,  1.0 ], \
    [  0.0,  1.0,  1.0 ], \
    [  0.0,  0.0,  2.0 ] ] )

  filename = 'tetrahedron_grid_display.png'

  tetrahedron_grid_display ( xv, ng, xg, filename )
#
#  Terminate.
#
  print ( '' )
  print ( 'TETRAHEDRON_GRID_DISPLAY_TEST:' )
  print ( '  Normal end of execution.' )
  return
  
if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  tetrahedron_grid_display_test ( )
  timestamp ( )