moved the quadratic error calculation out of the baker method, and added a cubic version too

This commit is contained in:
Stephen Mardson McQuay 2010-04-02 11:06:17 -06:00
parent 700ccc8c25
commit 3efe335563
2 changed files with 167 additions and 32 deletions

View File

@ -102,6 +102,88 @@ def qlinear_3D(X, R):
qlin = sum([q_i * phi_i for q_i, phi_i in zip(R.q, phis)])
return phis, qlin
def get_error_quadratic(phi, R, S):
B = [] # baker eq 9
w = [] # baker eq 11
for (s, q) in zip(S.points, S.q):
cur_phi, cur_qlin = qlinear(s, R)
(phi1, phi2, phi3) = cur_phi
B.append(
[
phi1 * phi2,
phi2 * phi3,
phi3 * phi1,
]
)
w.append(q - cur_qlin)
B = np.array(B)
w = np.array(w)
A = np.dot(B.T, B)
b = np.dot(B.T, w)
# baker solve eq 10
try:
(a, b, c) = np.linalg.solve(A,b)
except np.linalg.LinAlgError as e:
print >> sys.stderr, "warning: run_baker: linear calculation went bad, resorting to np.linalg.pinv", e
(a, b, c) = np.dot(np.linalg.pinv(A), b)
error_term = a * phi[0] * phi[1]\
+ b * phi[1] * phi[2]\
+ c * phi[2] * phi[0]
return error_term, a, b, c
def get_error_cubic(phi, R, S):
B = [] # baker eq 9
w = [] # baker eq 11
for (s, q) in zip(S.points, S.q):
cur_phi, cur_qlin = qlinear(s, R)
(phi1, phi2, phi3) = cur_phi
# basing this on eq 17
B.append(
[
phi1 * phi2, # a
phi1 * phi3, # b
phi2 * phi1, # c
phi2 * phi3, # d
phi3 * phi1, # e
phi3 * phi2, # f
phi1 * phi2 * phi3, # g
]
)
w.append(q - cur_qlin)
B = np.array(B)
w = np.array(w)
A = np.dot(B.T, B)
b = np.dot(B.T, w)
# baker solve eq 10
try:
(a, b, c, d, e, f, g) = np.linalg.solve(A,b)
except np.linalg.LinAlgError as e:
print >> sys.stderr, "warning: run_baker: linear calculation went bad, resorting to np.linalg.pinv", e
(a, b, c, d, e, f, g) = np.dot(np.linalg.pinv(A), b)
error_term = a * phi[0] * phi[1]\
+ b * phi[0] * phi[2]\
+ c * phi[1] * phi[0]\
+ d * phi[1] * phi[2]\
+ e * phi[2] * phi[0]\
+ f * phi[2] * phi[1]\
+ g * phi[0] * phi[1] * phi[2]\
return error_term, a, b, c
def run_baker(X, R, S, order=2):
"""
This is the main function to call to get an interpolation to X from the input meshes
@ -135,38 +217,12 @@ def run_baker(X, R, S, order=2):
}
return answer
B = [] # baker eq 9
w = [] # baker eq 11
for (s, q) in zip(S.points, S.q):
cur_phi, cur_qlin = qlinear(s, R)
(phi1, phi2, phi3) = cur_phi
B.append(
[
phi1 * phi2,
phi2 * phi3,
phi3 * phi1,
]
)
w.append(q - cur_qlin)
B = np.array(B)
w = np.array(w)
A = np.dot(B.T, B)
b = np.dot(B.T, w)
# baker solve eq 10
try:
(a, b, c) = np.linalg.solve(A,b)
except np.linalg.LinAlgError as e:
print >> sys.stderr, "warning: run_baker: linear calculation went bad, resorting to np.linalg.pinv", e
(a, b, c) = np.dot(np.linalg.pinv(A), b)
error_term = a * phi[0] * phi[1]\
+ b * phi[1] * phi[2]\
+ c * phi[2] * phi[0]
if order == 2:
error_term, a, b, c = get_error_quadratic(phi, R, S)
elif order == 3:
error_term, a, b, c = get_error_cubic(phi, R, S)
else:
raise smberror('unacceptable order for baker method')
q_final = qlin + error_term

79
test/cubic.test.py Executable file
View File

@ -0,0 +1,79 @@
#!/usr/bin/python
import unittest
import math
from baker import run_baker
from grid.DD import grid
from grid.simplex import contains
def exact_func(X):
x = X[0]
y = X[0]
return 1 - math.sin((x-0.5)**2 + (y-0.5)**2)
class TestSequenceFunctions(unittest.TestCase):
def setUp(self):
self.points = [
[ 0.25, 0.40], # 0
[ 0.60, 0.80], # 1
[ 0.65, 0.28], # 2
[ 0.28, 0.65], # 3
[ 1.00, 0.75], # 4
[ 0.30, 0.95], # 5
[ 0.80, 0.50], # 6
[ 0.35, 0.15], # 7
]
self.q = [exact_func(p) for p in self.points]
self.X = [0.25, 0.4001]
self.X = [0.55, 0.45]
self.g = grid(self.points, self.q)
self.g.construct_connectivity()
self.R = self.g.create_mesh(range(3))
self.exact = exact_func(self.X)
self.accuracy = 8
def test_R_contains_X(self):
self.assertTrue(contains(self.X, self.R.points))
def test_RunBaker_1_extra_point(self, extra=1):
S = self.g.create_mesh(range(3, 3 + extra))
answer = run_baker(self.X, self.R, S, order=3)
lin_err = abs(self.exact - answer['qlin'])
final_err = abs(self.exact - answer['final'])
self.assertTrue(lin_err >= final_err)
def test_RunBaker_2_extra_point(self, extra=2):
S = self.g.create_mesh(range(3, 3 + extra))
answer = run_baker(self.X, self.R, S, order=3)
lin_err = abs(self.exact - answer['qlin'])
final_err = abs(self.exact - answer['final'])
self.assertTrue(lin_err >= final_err)
def test_RunBaker_3_extra_point(self, extra=3):
S = self.g.create_mesh(range(3, 3 + extra))
answer = run_baker(self.X, self.R, S, order=3)
lin_err = abs(self.exact - answer['qlin'])
final_err = abs(self.exact - answer['final'])
self.assertTrue(lin_err >= final_err)
def test_RunBaker_4_extra_point(self, extra=4):
S = self.g.create_mesh(range(3, 3 + extra))
answer = run_baker(self.X, self.R, S, order=3)
lin_err = abs(self.exact - answer['qlin'])
final_err = abs(self.exact - answer['final'])
self.assertTrue(lin_err >= final_err)
def test_RunBaker_5_extra_point(self, extra=5):
S = self.g.create_mesh(range(3, 3 + extra))
answer = run_baker(self.X, self.R, S, order=3)
lin_err = abs(self.exact - answer['qlin'])
final_err = abs(self.exact - answer['final'])
self.assertTrue(lin_err >= final_err)
if __name__ == '__main__':
suite = unittest.TestLoader().loadTestsFromTestCase(TestSequenceFunctions)
unittest.TextTestRunner(verbosity=3).run(suite)