#! /usr/bin/env python
#
#  Modified:
#
#    23 February 2016
#
#  Author:
#
#    Jochen Garcke
#
#  Reference:
#
#    Jochen Garcke,
#    A sparse grid tutorial.
#
import pysg
import unittest
import math

class testFunctest(unittest.TestCase):
  """ simple test of sparse grid for sparse grid in 3d of level 3 """

  def testSGNoBound3D(self):
#
#  SG is a sparse grid of dimension 3 and level 3.
#  Create sg.indices which stores level and position for each point.
#
    sg = pysg.sparseGrid(3,3)
#
#  Determine sg.gP with the coordinates of the points 
#  associated with the sparse grid index set.
#
    sg.generatePoints()
#
#  Print the points in the grid.
#
    print ""
    print "Coordinates of points in 3D sparse grid of level 3."
    print ""
    for i in range ( len(sg.indices) ):
      sg.gP[tuple(sg.indices[i])].printPoint()
#
#  Did we compute the right number of grid points?
#
    self.assertEqual ( len ( sg.indices), 31 )
#
#  Evaluate 4x(1-x)*4y(1-y)*4z(1-z) at each grid point.
#
    for i in range ( len(sg.indices) ):
      sum = 1.0
      pos = sg.gP[tuple(sg.indices[i])].pos
      for j in range(len(pos)):
        sum *= 4.*pos[j]*(1.0-pos[j])
      sg.gP[tuple(sg.indices[i])].fv = sum
#
#  Convert the sparse grid from nodal to hierarchical values.
#
    sg.nodal2Hier()
#
#  Does the evaluation of the sparse grid function in
#  hierarchical values give the correct value gv?
#
    for i in range(len(sg.indices)):
      self.assertEqual(sg.gP[tuple(sg.indices[i])].fv,\
        sg.evalFunct(sg.gP[tuple(sg.indices[i])].pos))
  
  def testSGNoBound2D(self):
#
#  SG is a sparse grid of dimension 2 and level 3.
#  Create sg.indices which stores level and position for each point.
#    
    sg = pysg.sparseGrid(2,3)
#
#  Determine sg.gP with the coordinates of the points 
#  associated with the sparse grid index set.
#
    sg.generatePoints()
#
#  Print the points in the grid.
#
    print ""
    print "Coordinates of points in 2D sparse grid of level 3."
    print ""
    for i in range ( len(sg.indices) ):
      sg.gP[tuple(sg.indices[i])].printPoint()
#
#  Did we compute the right number of grid points?
#
    self.assertEqual(len(sg.indices),17)
#
#  Evaluate 4x(1-x)*4y(1-y) at each grid point.
#
    for i in range(len(sg.indices)):
      sum = 1.0
      pos = sg.gP[tuple(sg.indices[i])].pos
      for j in range(len(pos)):
        sum *= 4.*pos[j]*(1.0-pos[j])
      sg.gP[tuple(sg.indices[i])].fv = sum
#
#  Convert to hierarchical values.
#
    sg.nodal2Hier()
#
#  Does the evaluation of sparse grid function in
#  hierarchical values give the correct value gv?
#
    for i in range(len(sg.indices)):
      self.assertEqual(sg.gP[tuple(sg.indices[i])].fv,\
        sg.evalFunct(sg.gP[tuple(sg.indices[i])].pos))

if __name__=="__main__":
  unittest.main()