def test_all_models_have_pval(self):
losses = self.losses_df.iloc[:, :20]
mcs = MCS(losses, 0.05, reps=200)
mcs.seed(23456)
mcs.compute()
nan_locs = np.isnan(mcs.pvalues.iloc[:,0])
assert_true(not nan_locs.any())
def test_exact_ties(self):
losses = self.losses_df.iloc[:, :20].copy()
tied_mean = losses.mean().median()
losses.iloc[:, 10:] -= losses.iloc[:, 10:].mean()
losses.iloc[:, 10:] += tied_mean
mcs = MCS(losses, 0.05, reps=200)
mcs.seed(23456)
mcs.compute()
def test_str_repr(self):
mcs = MCS(self.losses, 0.05)
expected = 'MCS(size: 0.05, bootstrap: ' + str(mcs.bootstrap) + ')'
assert_equal(str(mcs), expected)
expected = expected[:-1] + ', ID: ' + hex(id(mcs)) + ')'
assert_equal(mcs.__repr__(), expected)
expected = ('<strong>MCS</strong>(' + '<strong>size</strong>: 0.05, ' +
'<strong>bootstrap</strong>: ' + str(mcs.bootstrap) +
', ' + '<strong>ID</strong>: ' + hex(id(mcs)) + ')')
assert_equal(mcs._repr_html_(), expected)
def test_str_repr(self):
mcs = MCS(self.losses, 0.05)
expected = 'MCS(size: 0.05, bootstrap: ' + str(mcs.bootstrap) + ')'
assert_equal(str(mcs), expected)
expected = expected[:-1] + ', ID: ' + hex(id(mcs)) + ')'
assert_equal(mcs.__repr__(), expected)
expected = ('<strong>MCS</strong>(' +
'<strong>size</strong>: 0.05, ' +
'<strong>bootstrap</strong>: ' + str(mcs.bootstrap) + ', ' +
'<strong>ID</strong>: ' + hex(id(mcs)) + ')')
assert_equal(mcs._repr_html_(), expected)
def test_r_method(self):
def r_step(losses, indices):
# A basic but direct implementation of the r method
t, k = losses.shape
b = len(indices)
mean_diffs = losses.mean(0)
loss_diffs = np.zeros((k, k))
variances = np.zeros((k, k))
bs_diffs = np.zeros(b)
stat_candidates = []
for i in range(k):
for j in range(i, k):
if i == j:
variances[i, i] = 1.0
loss_diffs[i, j] = 0.0
continue
loss_diffs_vec = losses[:, i] - losses[:, j]
loss_diffs_vec = loss_diffs_vec - loss_diffs_vec.mean()
loss_diffs[i, j] = mean_diffs[i] - mean_diffs[j]
loss_diffs[j, i] = mean_diffs[j] - mean_diffs[i]
for n in range(b):
# Compute bootstraped versions
bs_diffs[n] = loss_diffs_vec[indices[n]].mean()
variances[j, i] = variances[i, j] = (bs_diffs ** 2).mean()
stat_candidates.append(np.abs(bs_diffs) / np.sqrt(variances[i, j]))
stat_candidates = np.array(stat_candidates).T
stat_distn = np.max(stat_candidates, 1)
std_loss_diffs = loss_diffs / np.sqrt(variances)
stat = np.max(std_loss_diffs)
pval = np.mean(stat <= stat_distn)
loc = np.argwhere(std_loss_diffs == stat)
drop_index = loc.flat[0]
return pval, drop_index
losses = self.losses[:, :10] # Limit size
mcs = MCS(losses, 0.05, reps=200)
mcs.seed(23456)
mcs.compute()
m = 5 # Number of direct
pvals = np.zeros(m) * np.nan
indices = np.zeros(m) * np.nan
for i in range(m):
removed = list(indices[np.isfinite(indices)])
include = list(set(list(range(10))).difference(removed))
include.sort()
pval, drop_index = r_step(losses[:, np.array(include)], mcs._bootsrap_indices)
pvals[i] = pval if i == 0 else np.max([pvals[i - 1], pval])
indices[i] = include[drop_index]
direct = pd.DataFrame(pvals,
index=np.array(indices,dtype=np.int64),
columns=['Pvalue'])
direct.index.name = 'Model index'
assert_frame_equal(mcs.pvalues.iloc[:m], direct)
def test_smoke(self):
mcs = MCS(self.losses, 0.05, reps=100, block_size=10, method='max')
mcs.compute()
mcs = MCS(self.losses_df, 0.05, reps=100, block_size=10, method='r')
mcs.compute()
assert_equal(type(mcs.included), list)
assert_equal(type(mcs.excluded), list)
assert isinstance(mcs.pvalues, pd.DataFrame)
def test_errors(self):
with pytest.raises(ValueError):
MCS(self.losses[:, 1], 0.05)
mcs = MCS(self.losses,
0.05,
reps=100,
block_size=10,
method='max',
bootstrap='circular')
mcs.compute()
mcs = MCS(self.losses,
0.05,
reps=100,
block_size=10,
method='max',
bootstrap='moving block')
mcs.compute()
with pytest.raises(ValueError):
MCS(self.losses, 0.05, bootstrap='unknown')
def test_max_method(self):
def max_step(losses, indices):
# A basic but direct implementation of the max method
t, k = losses.shape
b = len(indices)
loss_errors = losses - losses.mean(0)
stats = np.zeros((b, k))
for n in range(b):
# Compute bootstraped versions
bs_loss_errors = loss_errors[indices[n]]
stats[n] = bs_loss_errors.mean(0) - bs_loss_errors.mean()
variances = (stats ** 2).mean(0)
std_devs = np.sqrt(variances)
stat_dist = np.max(stats / std_devs, 1)
test_stat = (losses.mean(0) - losses.mean())
std_test_stat = test_stat / std_devs
test_stat = np.max(std_test_stat)
pval = (test_stat < stat_dist).mean()
drop_index = np.argwhere(std_test_stat == test_stat).squeeze()
return pval, drop_index, std_devs
losses = self.losses[:, :10] # Limit size
mcs = MCS(losses, 0.05, reps=200, method='max')
mcs.seed(23456)
mcs.compute()
m = 8 # Number of direct
pvals = np.zeros(m) * np.nan
indices = np.zeros(m) * np.nan
for i in range(m):
removed = list(indices[np.isfinite(indices)])
include = list(set(list(range(10))).difference(removed))
include.sort()
pval, drop_index, std_devs = max_step(losses[:, np.array(include)], mcs._bootsrap_indices)
pvals[i] = pval if i == 0 else np.max([pvals[i - 1], pval])
indices[i] = include[drop_index]
direct = pd.DataFrame(pvals,
index=np.array(indices,dtype=np.int64),
columns=['Pvalue'])
direct.index.name = 'Model index'
assert_frame_equal(mcs.pvalues.iloc[:m], direct)
def test_errors(self):
assert_raises(ValueError, MCS, self.losses[:,1], 0.05)
mcs = MCS(self.losses, 0.05, reps=100, block_size=10, method='max', bootstrap='circular')
mcs.compute()
mcs = MCS(self.losses, 0.05, reps=100, block_size=10, method='max', bootstrap='moving block')
mcs.compute()
assert_raises(ValueError, MCS, self.losses, 0.05, bootstrap='unknown')
def test_all_models_have_pval(self):
losses = self.losses_df.iloc[:, :20]
mcs = MCS(losses, 0.05, reps=200)
mcs.seed(23456)
mcs.compute()
nan_locs = np.isnan(mcs.pvalues.iloc[:, 0])
assert not nan_locs.any()
def test_smoke(self):
mcs = MCS(self.losses, 0.05, reps=100, block_size=10, method='max')
mcs.compute()
mcs = MCS(self.losses_df, 0.05, reps=100, block_size=10, method='r')
mcs.compute()
assert_equal(type(mcs.included), list)
assert_equal(type(mcs.excluded), list)
assert_true(isinstance(mcs.pvalues, pd.DataFrame))
def test_exact_ties(self):
losses = self.losses_df.iloc[:, :20].copy()
tied_mean = losses.mean().median()
losses.iloc[:, 10:] -= losses.iloc[:, 10:].mean()
losses.iloc[:, 10:] += tied_mean
mcs = MCS(losses, 0.05, reps=200)
mcs.seed(23456)
mcs.compute()
def test_r_method(self):
def r_step(losses, indices):
# A basic but direct implementation of the r method
t, k = losses.shape
b = len(indices)
mean_diffs = losses.mean(0)
loss_diffs = np.zeros((k, k))
variances = np.zeros((k, k))
bs_diffs = np.zeros(b)
stat_candidates = []
for i in range(k):
for j in range(i, k):
if i == j:
variances[i, i] = 1.0
loss_diffs[i, j] = 0.0
continue
loss_diffs_vec = losses[:, i] - losses[:, j]
loss_diffs_vec = loss_diffs_vec - loss_diffs_vec.mean()
loss_diffs[i, j] = mean_diffs[i] - mean_diffs[j]
loss_diffs[j, i] = mean_diffs[j] - mean_diffs[i]
for n in range(b):
# Compute bootstraped versions
bs_diffs[n] = loss_diffs_vec[indices[n]].mean()
variances[j, i] = variances[i, j] = (bs_diffs**2).mean()
stat_candidates.append(
np.abs(bs_diffs) / np.sqrt(variances[i, j]))
stat_candidates = np.array(stat_candidates).T
stat_distn = np.max(stat_candidates, 1)
std_loss_diffs = loss_diffs / np.sqrt(variances)
stat = np.max(std_loss_diffs)
pval = np.mean(stat <= stat_distn)
loc = np.argwhere(std_loss_diffs == stat)
drop_index = loc.flat[0]
return pval, drop_index
losses = self.losses[:, :10] # Limit size
mcs = MCS(losses, 0.05, reps=200)
mcs.seed(23456)
mcs.compute()
m = 5 # Number of direct
pvals = np.zeros(m) * np.nan
indices = np.zeros(m) * np.nan
for i in range(m):
removed = list(indices[np.isfinite(indices)])
include = list(set(list(range(10))).difference(removed))
include.sort()
pval, drop_index = r_step(losses[:, np.array(include)],
mcs._bootsrap_indices)
pvals[i] = pval if i == 0 else np.max([pvals[i - 1], pval])
indices[i] = include[drop_index]
direct = pd.DataFrame(pvals,
index=np.array(indices, dtype=np.int64),
columns=['Pvalue'])
direct.index.name = 'Model index'
assert_frame_equal(mcs.pvalues.iloc[:m], direct)
def test_max_method(self):
def max_step(losses, indices):
# A basic but direct implementation of the max method
t, k = losses.shape
b = len(indices)
loss_errors = losses - losses.mean(0)
stats = np.zeros((b, k))
for n in range(b):
# Compute bootstraped versions
bs_loss_errors = loss_errors[indices[n]]
stats[n] = bs_loss_errors.mean(0) - bs_loss_errors.mean()
variances = (stats**2).mean(0)
std_devs = np.sqrt(variances)
stat_dist = np.max(stats / std_devs, 1)
test_stat = (losses.mean(0) - losses.mean())
std_test_stat = test_stat / std_devs
test_stat = np.max(std_test_stat)
pval = (test_stat < stat_dist).mean()
drop_index = np.argwhere(std_test_stat == test_stat).squeeze()
return pval, drop_index, std_devs
losses = self.losses[:, :10] # Limit size
mcs = MCS(losses, 0.05, reps=200, method='max')
mcs.seed(23456)
mcs.compute()
m = 8 # Number of direct
pvals = np.zeros(m) * np.nan
indices = np.zeros(m) * np.nan
for i in range(m):
removed = list(indices[np.isfinite(indices)])
include = list(set(list(range(10))).difference(removed))
include.sort()
pval, drop_index, std_devs = max_step(losses[:,
np.array(include)],
mcs._bootsrap_indices)
pvals[i] = pval if i == 0 else np.max([pvals[i - 1], pval])
indices[i] = include[drop_index]
direct = pd.DataFrame(pvals,
index=np.array(indices, dtype=np.int64),
columns=['Pvalue'])
direct.index.name = 'Model index'
assert_frame_equal(mcs.pvalues.iloc[:m], direct)
