from libtbx.test_utils import approx_equal

def exercise_integer():
  from libtbx.math_utils import iround, iceil, ifloor
  assert iround(0) == 0
  assert iround(1.4) == 1
  assert iround(-1.4) == -1
  assert iround(1.6) == 2
  assert iround(-1.6) == -2
  assert iceil(0) == 0
  assert iceil(1.1) == 2
  assert iceil(-1.1) == -1
  assert iceil(1.9) == 2
  assert iceil(-1.9) == -1
  assert ifloor(0) == 0
  assert ifloor(1.1) == 1
  assert ifloor(-1.1) == -2
  assert ifloor(1.9) == 1
  assert ifloor(-1.9) == -2

def exercise_logical():
  from libtbx.math_utils import does_imply, are_equivalent
  #
  assert does_imply(True, True)
  assert not does_imply(True, False)
  assert does_imply(False, True)
  assert does_imply(False, False)
  #
  assert are_equivalent(True, True)
  assert not are_equivalent(True, False)
  assert not are_equivalent(False, True)
  assert are_equivalent(False, False)

def exercise_next_permutation():
  from libtbx.math_utils import next_permutation
  seq = []
  assert next_permutation(seq) is False
  seq = [0]
  assert next_permutation(seq) is False
  seq = [0,1]
  assert next_permutation(seq)
  assert seq == [1, 0]
  assert not next_permutation(seq)
  assert seq == [0, 1]
  seq = [0,1,2]
  result = []
  while True:
    result.append(tuple(seq))
    if (not next_permutation(seq)):
      break
  assert result == [
    (0, 1, 2),
    (0, 2, 1),
    (1, 0, 2),
    (1, 2, 0),
    (2, 0, 1),
    (2, 1, 0)]
  assert seq == [0,1,2]
  expected_n = 1
  for m in xrange(1,7):
    expected_n *= m
    seq = range(m)
    n = 0
    while True:
      n += 1
      if (not next_permutation(seq)):
        break
    assert seq == range(m)
    assert n == expected_n

def exercise_normalize_angle():
  from libtbx.math_utils import normalize_angle as n
  import math
  for deg,period in [(False, 2*math.pi), (True, 360.)]:
    assert approx_equal(n(0, deg=deg), 0, eps=1.e-12)
    assert approx_equal(n(1.e-8, deg=deg), 1.e-8, eps=1.e-12)
    assert approx_equal(n(-1.e-8, deg=deg), period-1.e-8, eps=1.e-12)
    assert approx_equal(n(1, deg=deg), 1, eps=1.e-12)
    assert approx_equal(n(-1, deg=deg), period-1, eps=1.e-12)
  assert approx_equal(n(1.e+8), 1.9426951384)
  assert approx_equal(n(-1.e+8), 4.34049016878)
  assert approx_equal(n(1.e+8, deg=True), 280)
  assert approx_equal(n(-1.e+8, deg=True), 80)

def exercise():
  exercise_integer()
  exercise_logical()
  exercise_next_permutation()
  exercise_normalize_angle()
  print "OK"

if (__name__ == "__main__"):
  exercise()