def runTest(self):
# Test against np.linalg.lstsq
# m = 1
n, npt = 5, 3
np.random.seed(0) # (fixing random seed)
A = np.random.rand(npt, n)
b = np.random.rand(npt)
x0 = np.zeros((n,))
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
# model = Model(n+1, x0, np.array([0.0]), xl, xu, 1)
model = Model(n+1, A[0, :], np.array([b[0]]), xl, xu, 1)
for i in range(1,npt):
xi = A[i,:]
model.change_point(i, xi - model.xbase, b[i])
xopt = model.xopt(abs_coordinates=True)
A_for_interp = np.zeros((npt, n + 1)) # there are actually npt+1 points
A_for_interp[:, 0] = 1.0 # constant terms
for i in range(npt):
A_for_interp[i, 1:] = A[i, :] - xopt
A2, left_scaling, right_scaling = model.interpolation_matrix()
A_after_scaling = np.dot(np.diag(1.0 / left_scaling), np.dot(A2, np.diag(1.0 / right_scaling))) # undo scaling
self.assertTrue(array_compare(A_for_interp, A_after_scaling), 'Interp matrix 1')
# For reference: model based around model.xbase
interp_ok, interp_error, norm_J_error, linalg_resid, ls_interp_cond_num = model.interpolate_mini_models_svd()
self.assertTrue(interp_ok, 'Interpolation failed')
J_true = np.linalg.lstsq(A_for_interp, b, rcond=None)[0]
g = J_true[1:]
c = J_true[0] - np.dot(g, model.xopt()) # centred at xbase
self.assertTrue(array_compare(model.model_const, np.array([c])), 'Wrong constant term')
self.assertTrue(array_compare(model.model_jac, g), 'Wrong Jacobian term')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
delta = 0.5
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
model.add_new_sample(0, rosenbrock(x0))
x1 = x0 + delta * np.array([1.0, 0.0])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
x2 = x0 + delta * np.array([0.0, 1.0])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
model.kopt = 0 # force this
# Here (use delta=1), Lagrange polynomials are (1-x-y), 1-x and 1-y
# Maximum value in ball is for (1-x-y) at (x,y)=(1/sqrt2, 1/sqrt2) --> max value = 1 + sqrt(2)
self.assertTrue(abs(model.poisedness_constant(delta) - 1.0 - sqrt(2.0)) < 1e-6, 'Poisedness constant wrong')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
x1 = np.array([1.0, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
x2 = np.array([1.0, 1.0])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
self.assertEqual(model.kopt, 2, 'Wrong kopt before resampling')
# Originally, x2 is the ideal point
# Here, testing that kopt moves back to x1 after adding heaps of bad x2 samples
for i in range(10):
model.add_new_sample(2, np.array([5.0, 5.0]))
self.assertEqual(model.kopt, 1, 'Wrong kopt after resampling')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e20 * np.ones((n,))
xu = 1e20 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
# Now add better point
x1 = np.array([1.0, 0.9])
rvec = rosenbrock(x1)
model.change_point(1, x1 - model.xbase, rvec, allow_kopt_update=True)
# Now add worse point
x2 = np.array([2.0, 0.9])
rvec = rosenbrock(x2)
model.change_point(2, x2 - model.xbase, rvec, allow_kopt_update=True)
model.swap_points(0, 2)
self.assertTrue(array_compare(model.xpt(0, abs_coordinates=True), x2), 'Wrong xpt(0) after swap 1')
self.assertTrue(array_compare(model.xpt(1, abs_coordinates=True), x1), 'Wrong xpt(1) after swap 1')
self.assertTrue(array_compare(model.xpt(2, abs_coordinates=True), x0), 'Wrong xpt(2) after swap 1')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), x1), 'Wrong xopt after swap 1')
model.swap_points(1, 2)
self.assertTrue(array_compare(model.xpt(0, abs_coordinates=True), x2), 'Wrong xpt(0) after swap 2')
self.assertTrue(array_compare(model.xpt(1, abs_coordinates=True), x0), 'Wrong xpt(1) after swap 2')
self.assertTrue(array_compare(model.xpt(2, abs_coordinates=True), x1), 'Wrong xpt(2) after swap 2')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), x1), 'Wrong xopt after swap 2')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e20 * np.ones((n,))
xu = 1e20 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
self.assertEqual(model.npt(), 1, 'Wrong npt after initialisation')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), x0), 'Wrong xopt after initialisation')
self.assertTrue(array_compare(model.ropt(), rosenbrock(x0)), 'Wrong ropt after initialisation')
self.assertAlmostEqual(model.fopt(), sumsq(rosenbrock(x0)), 'Wrong fopt after initialisation')
# Now add better point
x1 = np.array([1.0, 0.9])
rvec = rosenbrock(x1)
model.change_point(1, x1 - model.xbase, rvec, allow_kopt_update=True)
self.assertEqual(model.npt(), 2, 'Wrong npt after x1')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), x1), 'Wrong xopt after x1')
self.assertTrue(array_compare(model.ropt(), rosenbrock(x1)), 'Wrong ropt after x1')
self.assertAlmostEqual(model.fopt(), sumsq(rosenbrock(x1)), 'Wrong fopt after x1')
# Now add worse point
x2 = np.array([2.0, 0.9])
rvec = rosenbrock(x2)
model.change_point(2, x2 - model.xbase, rvec, allow_kopt_update=True)
self.assertEqual(model.npt(), 3, 'Wrong npt after x2')
self.assertTrue(array_compare(model.xpt(0, abs_coordinates=True), x0), 'Wrong xpt(0) after x2')
self.assertTrue(array_compare(model.xpt(1, abs_coordinates=True), x1), 'Wrong xpt(1) after x2')
self.assertTrue(array_compare(model.xpt(2, abs_coordinates=True), x2), 'Wrong xpt(2) after x2')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), x1), 'Wrong xopt after x2')
self.assertTrue(array_compare(model.ropt(), rosenbrock(x1)), 'Wrong ropt after x2')
self.assertAlmostEqual(model.fopt(), sumsq(rosenbrock(x1)), 'Wrong fopt after x2')
# Now add best point (but don't update kopt)
x3 = np.array([1.0, 1.0])
rvec = rosenbrock(x3)
model.change_point(0, x3 - model.xbase, rvec, allow_kopt_update=False) # full: overwrite x0
self.assertEqual(model.npt(), 3, 'Wrong npt after x3')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), x1), 'Wrong xopt after x3')
self.assertTrue(array_compare(model.ropt(), rosenbrock(x1)), 'Wrong ropt after x3')
self.assertAlmostEqual(model.fopt(), sumsq(rosenbrock(x1)), 'Wrong fopt after x3')
self.assertTrue(array_compare(model.xopt(abs_coordinates=True), model.as_absolute_coordinates(model.xopt())),
'Comparison wrong after x3')
dirns = model.xpt_directions(include_kopt=True)
self.assertTrue(array_compare(x3 - x1, dirns[0, :]), 'Wrong dirn 0')
self.assertTrue(array_compare(x1 - x1, dirns[1, :]), 'Wrong dirn 1')
self.assertTrue(array_compare(x2 - x1, dirns[2, :]), 'Wrong dirn 2')
dirns = model.xpt_directions(include_kopt=False)
self.assertTrue(array_compare(x3 - x1, dirns[0, :]), 'Wrong dirn 0 (no kopt)')
# self.assertTrue(array_compare(x1 - x1, dirns[1, :]), 'Wrong dirn 1')
self.assertTrue(array_compare(x2 - x1, dirns[1, :]), 'Wrong dirn 1 (no kopt)')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
x1 = np.array([1.0, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
x2 = np.array([2.0, 0.9])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
# Now add a new point
x3 = np.array([1.0, 1.0]) # good point
model.add_new_point(x3 - model.xbase, rosenbrock(x3))
self.assertEqual(model.npt(), 4, "Wrong number of points after x3")
self.assertTrue(array_compare(model.xpt(3, abs_coordinates=True), x3), "Wrong new point after x3")
self.assertTrue(array_compare(model.rvec(3), rosenbrock(x3)), "Wrong rvec after x3")
self.assertEqual(model.kopt, 3, "Wrong kopt after x3")
self.assertEqual(len(model.nsamples), 4, "Wrong nsamples length after x3")
self.assertEqual(model.nsamples[-1], 1, "Wrong nsample value after x3")
x4 = np.array([-1.8, 1.8]) # bad point
model.add_new_point(x4 - model.xbase, rosenbrock(x4))
self.assertEqual(model.npt(), 5, "Wrong number of points after x4")
self.assertTrue(array_compare(model.xpt(4, abs_coordinates=True), x4), "Wrong new point after x4")
self.assertTrue(array_compare(model.rvec(4), rosenbrock(x4)), "Wrong rvec after x4")
self.assertEqual(model.kopt, 3, "Wrong kopt after x4")
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
model.add_new_sample(0, rosenbrock(x0))
x1 = np.array([-1.2, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
# Here, x0 is base
# A = model.interpolation_matrix()
# self.assertTrue(array_compare(A[1, :], delta * np.array([1.0, 0.0])), 'Bad padded interp matrix')
old_jac = model.model_jac.copy()
model.interpolate_mini_models_svd(make_full_rank=False)
J = model.model_jac.copy()
model.model_jac = old_jac # reset
sng_vals = np.linalg.svd(J)[1]
model.interpolate_mini_models_svd(make_full_rank=True)
J2 = model.model_jac.copy()
sng_vals2 = np.linalg.svd(J2)[1]
print("Original", sng_vals)
print("After making full rank", sng_vals2)
self.assertTrue(10*sng_vals[-1] < sng_vals2[-1], 'New singular value too small')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
# x0 = np.array([1.0, 2.9])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
model.add_new_sample(0, rosenbrock(x0))
x1 = np.array([1.0, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
x2 = np.array([2.0, 0.9])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
c0, g0 = model.lagrange_gradient(0)
lag_thresh = 1e-10
xopt = model.xopt(abs_coordinates=True)
# print(c0 + np.dot(g0, x0 - xopt), c0, g0)
self.assertTrue(abs(c0 + np.dot(g0, x0 - xopt) - 1.0) < lag_thresh, 'Bad L0(x0)')
self.assertTrue(abs(c0 + np.dot(g0, x1 - xopt) - 0.0) < lag_thresh, 'Bad L0(x1)')
self.assertTrue(abs(c0 + np.dot(g0, x2 - xopt) - 0.0) < lag_thresh, 'Bad L0(x2)')
c1, g1 = model.lagrange_gradient(1)
# print(c1 + np.dot(g1, x0 - xopt), c1, g1)
self.assertTrue(abs(c1 + np.dot(g1, x0 - xopt) - 0.0) < lag_thresh, 'Bad L1(x0)')
self.assertTrue(abs(c1 + np.dot(g1, x1 - xopt) - 1.0) < lag_thresh, 'Bad L1(x1)')
self.assertTrue(abs(c1 + np.dot(g1, x2 - xopt) - 0.0) < lag_thresh, 'Bad L1(x2)')
c2, g2 = model.lagrange_gradient(2)
self.assertTrue(abs(c2 + np.dot(g2, x0 - xopt) - 0.0) < lag_thresh, 'Bad L2(x0)')
self.assertTrue(abs(c2 + np.dot(g2, x1 - xopt) - 0.0) < lag_thresh, 'Bad L2(x1)')
self.assertTrue(abs(c2 + np.dot(g2, x2 - xopt) - 1.0) < lag_thresh, 'Bad L2(x2)')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
model.add_new_sample(0, rosenbrock(x0))
x1 = np.array([1.0, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
x2 = np.array([2.0, 0.9])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
A, left_scaling, right_scaling = model.interpolation_matrix()
A_expect = np.ones((3, 3))
A_expect[0, 1:] = x0 - x1
A_expect[1, 1:] = x1 - x1 # x1 is xopt in this situation
A_expect[2, 1:] = x2 - x1
A_after_scaling = np.dot(np.diag(1.0 / left_scaling), np.dot(A, np.diag(1.0 / right_scaling)))
self.assertTrue(array_compare(A_after_scaling, A_expect), 'Interp matrix 1')
# For reference: model based around model.xbase
interp_ok, interp_error, norm_J_error, linalg_resid, ls_interp_cond_num = model.interpolate_mini_models_svd()
self.assertTrue(interp_ok, 'Interpolation failed')
# print(x0, x1, x2)
# print(rosenbrock(x0), rosenbrock(x1), rosenbrock(x2))
# print("xbase =", model.xbase)
# print("xopt =", model.xopt(abs_coordinates=True))
# print(model.model_const, rosenbrock(model.xbase))
self.assertTrue(array_compare(model.model_const, rosenbrock(model.xbase), thresh=1e-10), 'Wrong constant term')
self.assertTrue(array_compare(model.model_value(x0 - model.xbase, d_based_at_xopt=False, with_const_term=True),
rosenbrock(x0), thresh=1e-10), 'Wrong x0') # allow some inexactness
self.assertTrue(array_compare(model.model_value(x1 - model.xbase, d_based_at_xopt=False, with_const_term=True),
rosenbrock(x1), thresh=1e-10), 'Wrong x1') # allow some inexactness
self.assertTrue(array_compare(model.model_value(x2 - model.xbase, d_based_at_xopt=False, with_const_term=True),
rosenbrock(x2), thresh=1e-10), 'Wrong x2')
# Test some other parameter settings for model.model_value()
self.assertTrue(array_compare(model.model_value(x2 - x1, d_based_at_xopt=True, with_const_term=True),
rosenbrock(x2), thresh=1e-10), 'Wrong x2 (from xopt)')
self.assertTrue(array_compare(model.model_value(x2 - x1, d_based_at_xopt=True, with_const_term=False),
rosenbrock(x2)-rosenbrock(model.xbase), thresh=1e-10), 'Wrong x2 (no constant)')
self.assertTrue(array_compare(model.model_value(x2 - model.xbase, d_based_at_xopt=False, with_const_term=False),
rosenbrock(x2) - rosenbrock(model.xbase), thresh=1e-10), 'Wrong x2 (no constant v2)')
g, H = model.build_full_model()
r = rosenbrock(x1)
J = model.model_jac
self.assertTrue(array_compare(g, 2.0*np.dot(J.T, r), thresh=1e-10), 'Bad gradient')
self.assertTrue(array_compare(H, 2.0*np.dot(J.T, J)), 'Bad Hessian')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
x1 = np.array([1.0, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
x2 = np.array([2.0, 0.9])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
self.assertAlmostEqual(model.min_objective_value(), 1e-12, 'Wrong min obj value')
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1, rel_tol=1e-2)
self.assertAlmostEqual(model.min_objective_value(), 1e-2 * sumsq(rosenbrock(x0)), 'Wrong min obj value 2')
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1, abs_tol=1.0)
self.assertAlmostEqual(model.min_objective_value(), 1.0, 'Wrong min obj value 3')
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1, abs_tol=1.0, rel_tol=1e-2)
self.assertAlmostEqual(model.min_objective_value(), 1.0, 'Wrong min obj value 4')
def runTest(self):
n, m = 2, 2
npt = n + 1
x0 = np.array([-1.2, 1.0])
xl = -1e2 * np.ones((n,))
xu = 1e2 * np.ones((n,))
model = Model(npt, x0, rosenbrock(x0), xl, xu, 1)
self.assertTrue(array_compare(model.sl, xl - x0), 'Wrong sl after initialisation')
self.assertTrue(array_compare(model.su, xu - x0), 'Wrong su after initialisation')
x1 = np.array([1.0, 0.9])
model.change_point(1, x1 - model.xbase, rosenbrock(x1))
self.assertTrue(array_compare(model.as_absolute_coordinates(x1 - x0), x1), 'Wrong abs coords')
self.assertTrue(array_compare(model.as_absolute_coordinates(np.array([-1e3, 1e3])-x0), np.array([-1e2, 1e2])),
'Bad abs coords with bounds')
x2 = np.array([2.0, 0.9])
model.change_point(2, x2 - model.xbase, rosenbrock(x2))
sqdists = model.distances_to_xopt()
self.assertAlmostEqual(sqdists[0], sumsq(x0 - x1), 'Wrong distance 0')
self.assertAlmostEqual(sqdists[1], sumsq(x1 - x1), 'Wrong distance 1')
self.assertAlmostEqual(sqdists[2], sumsq(x2 - x1), 'Wrong distance 2')
model.add_new_sample(0, rosenbrock(x0))
self.assertEqual(model.nsamples[0], 2, 'Wrong number of samples 0')
self.assertEqual(model.nsamples[1], 1, 'Wrong number of samples 1')
self.assertEqual(model.nsamples[2], 1, 'Wrong number of samples 2')
for i in range(50):
model.add_new_sample(0, np.array([0.0, 0.0]))
self.assertEqual(model.kopt, 0, 'Wrong kopt after bad resampling')
self.assertTrue(array_compare(model.ropt(), 2*rosenbrock(x0)/52), 'Wrong ropt after bad resampling')
self.assertAlmostEqual(model.fopt(), sumsq(2 * rosenbrock(x0) / 52), 'Wrong fopt after bad resampling')
d = np.array([10.0, 10.0])
dirns_old = model.xpt_directions(include_kopt=True)
model.shift_base(d)
dirns_new = model.xpt_directions(include_kopt=True)
self.assertTrue(array_compare(model.xbase, x0 + d), 'Wrong new base')
self.assertEqual(model.kopt, 0, 'Wrong kopt after shift base')
for i in range(3):
self.assertTrue(array_compare(dirns_old[i, :], dirns_new[i, :]), 'Wrong dirn %i after shift base' % i)
self.assertTrue(array_compare(model.sl, xl - x0 - d), 'Wrong sl after shift base')
self.assertTrue(array_compare(model.su, xu - x0 - d), 'Wrong su after shift base')
# save_point and get_final_results
model.change_point(0, x0 - model.xbase, rosenbrock(x0)) # revert after resampling
model.change_point(1, x1 - model.xbase, rosenbrock(x1)) # revert after resampling
x, rvec, f, jacmin, nsamples = model.get_final_results()
self.assertTrue(array_compare(x, x1), 'Wrong final x')
self.assertTrue(array_compare(rvec, rosenbrock(x1)), 'Wrong final rvec')
self.assertAlmostEqual(sumsq(rosenbrock(x1)), f, 'Wrong final f')
self.assertTrue(array_compare(np.zeros((2,2)), jacmin), 'Wrong final jacmin')
self.assertEqual(1, nsamples, 'Wrong final nsamples')
self.assertIsNone(model.xsave, 'xsave not none after initialisation')
self.assertIsNone(model.rsave, 'rsave not none after initialisation')
self.assertIsNone(model.fsave, 'fsave not none after initialisation')
self.assertIsNone(model.nsamples_save, 'nsamples_save not none after initialisation')
model.save_point(x0, rosenbrock(x0), 1, x_in_abs_coords=True)
self.assertTrue(array_compare(model.xsave, x0), 'Wrong xsave after saving')
self.assertTrue(array_compare(model.rsave, rosenbrock(x0)), 'Wrong rsave after saving')
self.assertAlmostEqual(model.fsave, sumsq(rosenbrock(x0)), 'Wrong fsave after saving')
self.assertEqual(model.nsamples_save, 1, 'Wrong nsamples_save after saving')
x, rvec, f, jacmin, nsamples = model.get_final_results()
self.assertTrue(array_compare(x, x1), 'Wrong final x after saving')
self.assertTrue(array_compare(rvec, rosenbrock(x1)), 'Wrong final rvec after saving')
self.assertAlmostEqual(sumsq(rosenbrock(x1)), f, 'Wrong final f after saving')
self.assertEqual(1, nsamples, 'Wrong final nsamples after saving')
model.save_point(x2 - model.xbase, np.array([0.0, 0.0]), 2, x_in_abs_coords=False)
self.assertTrue(array_compare(model.xsave, x2), 'Wrong xsave after saving 2')
self.assertTrue(array_compare(model.rsave, np.array([0.0, 0.0])), 'Wrong rsave after saving 2')
self.assertAlmostEqual(model.fsave, 0.0, 'Wrong fsave after saving 2')
self.assertEqual(model.nsamples_save, 2, 'Wrong nsamples_save after saving 2')
x, rvec, f, jacmin, nsamples = model.get_final_results()
self.assertTrue(array_compare(x, x2), 'Wrong final x after saving 2')
self.assertTrue(array_compare(rvec, np.array([0.0, 0.0])), 'Wrong final rvec after saving 2')
self.assertAlmostEqual(f, 0.0, 'Wrong final f after saving 2')
self.assertEqual(2, nsamples, 'Wrong final nsamples after saving 2')
model.save_point(x0, rosenbrock(x0), 3, x_in_abs_coords=True) # try to re-save a worse value
self.assertTrue(array_compare(model.xsave, x2), 'Wrong xsave after saving 3')
self.assertTrue(array_compare(model.rsave, np.array([0.0, 0.0])), 'Wrong rsave after saving 3')
self.assertAlmostEqual(model.fsave, 0.0, 'Wrong fsave after saving 3')
self.assertEqual(model.nsamples_save, 2, 'Wrong nsamples_save after saving 3')