def test_high_n_lat(self):
x1, x2, y1, y2 = qc.get_four_surrounding_points(89.9, 0.1, 1)
self.assertEqual(x1, -0.5)
self.assertEqual(x2, 0.5)
self.assertEqual(y1, 89.5)
self.assertEqual(y2, 89.5)
x1, x2, y1, y2 = qc.get_four_surrounding_points(89.9, 0.1, 0)
self.assertEqual(x1, -0.5)
self.assertEqual(x2, 0.5)
self.assertEqual(y1, 89.5)
self.assertEqual(y2, 90.5)
def test_negative_dateline_crossover(self):
x1, x2, y1, y2 = qc.get_four_surrounding_points(0.0, -179.9)
self.assertEqual(x1, -180.5)
self.assertEqual(x2, -179.5)
self.assertEqual(y1, -0.5)
self.assertEqual(y2, 0.5)
def test_zero_zero(self):
x1, x2, y1, y2 = qc.get_four_surrounding_points(0.0, 0.0)
self.assertEqual(x1, -0.5)
self.assertEqual(x2, 0.5)
self.assertEqual(y1, -0.5)
self.assertEqual(y2, 0.5)
def test_high_lon(self):
x1, x2, y1, y2 = qc.get_four_surrounding_points(0.4, 322.2 - 360, 1)
self.assertEqual(x1, -38.5)
self.assertEqual(x2, -37.5)
self.assertEqual(y1, -0.5)
self.assertEqual(y2, 0.5)
def get_interpolated_value(self, lat, lon, mo, dy):
'''
Get the value from the climatology interpolated to the precise location of
the observation in time and space
:param lat: latitude of location to extract value from in degrees
:param lon: longitude of location to extract value from in degrees
:param month: month for which the value is required
:param day: day for which the value is required
:type lat: float
:type lon: float
:type month: integer
:type day: integer
:return: climatology value at specified location and time.
:rtype: float
'''
#check that the lat lon point falls in a grid cell with a value or on
#the border of one
if lat + 0.001 < 90:
pert1 = self.get_value(lat + 0.001, lon + 0.001, mo, dy)
pert2 = self.get_value(lat + 0.001, lon - 0.001, mo, dy)
else:
pert1 = None
pert2 = None
if lat - 0.001 > -90:
pert3 = self.get_value(lat - 0.001, lon + 0.001, mo, dy)
pert4 = self.get_value(lat - 0.001, lon - 0.001, mo, dy)
else:
pert3 = None
pert4 = None
if (pert1 == None and pert2 == None and pert3 == None
and pert4 == None):
return None
x1, x2, y1, y2 = qc.get_four_surrounding_points(lat, lon, 1)
try:
Q11 = self.get_value(y1, x1, mo, dy)
except:
Q11 = None
if Q11 != None:
Q11 = float(Q11)
try:
Q22 = self.get_value(y2, x2, mo, dy)
except:
Q22 = None
if Q22 != None:
Q22 = float(Q22)
try:
Q12 = self.get_value(y2, x1, mo, dy)
except:
Q12 = None
if Q12 != None:
Q12 = float(Q12)
try:
Q21 = self.get_value(y1, x2, mo, dy)
except:
Q21 = None
if Q21 != None:
Q21 = float(Q21)
Q11, Q12, Q21, Q22 = qc.fill_missing_vals(Q11, Q12, Q21, Q22)
x1, x2, y1, y2 = qc.get_four_surrounding_points(lat, lon, 0)
return qc.bilinear_interp(x1, x2, y1, y2, lon, lat, Q11, Q12, Q21, Q22)
