# Python numpy.log() 使用实例

Example 1

def svgd_kernel(self, h = -1):
sq_dist = pdist(self.theta)
pairwise_dists = squareform(sq_dist)**2
if h < 0: # if h < 0, using median trick
h = np.median(pairwise_dists)
h = np.sqrt(0.5 * h / np.log(self.theta.shape[0]+1))

# compute the rbf kernel

Kxy = np.exp( -pairwise_dists / h**2 / 2)

dxkxy = -np.matmul(Kxy, self.theta)
sumkxy = np.sum(Kxy, axis=1)
for i in range(self.theta.shape[1]):
dxkxy[:, i] = dxkxy[:,i] + np.multiply(self.theta[:,i],sumkxy)
dxkxy = dxkxy / (h**2)
return (Kxy, dxkxy) 

Example 2

def saveHintonPlot(self, matrix, num_tests, max_weight=None, ax=None):
"""Draw Hinton diagram for visualizing a weight matrix."""
fig,ax = plt.subplots(1,1)

if not max_weight:
max_weight = 2**np.ceil(np.log(np.abs(matrix).max())/np.log(2))

ax.patch.set_facecolor('gray')
ax.set_aspect('equal', 'box')
ax.xaxis.set_major_locator(plt.NullLocator())
ax.yaxis.set_major_locator(plt.NullLocator())

for (x, y), w in np.ndenumerate(matrix):
color = 'white' if w > 0 else 'black'
size = np.sqrt(np.abs(0.5*w/num_tests)) # Need to scale so that it is between 0 and 0.5
rect = plt.Rectangle([x - size / 2, y - size / 2], size, size,
facecolor=color, edgecolor=color)

ax.autoscale_view()
ax.invert_yaxis()
plt.savefig(self.figures_path + self.save_prefix + '-Hinton.eps')
plt.close() 

Example 3

def _factor_target_indices(self, Y_inds, vocab_size=None, base=2):
if vocab_size is None:
vocab_size = len(self.dp.word_index)
print >>sys.stderr, "Factoring targets of vocabulary size: %d"%(vocab_size)
num_vecs = int(math.ceil(math.log(vocab_size)/math.log(base))) + 1
base_inds = []
div_Y_inds = Y_inds
print >>sys.stderr, "Number of factors: %d"%num_vecs
for i in range(num_vecs):
new_inds = div_Y_inds % base
if i == num_vecs - 1:
if new_inds.sum() == 0:
# Most significant "digit" is a zero. Omit it.
break
base_inds.append(new_inds)
div_Y_inds = numpy.copy(div_Y_inds/base)
base_vecs = [self._make_one_hot(base_inds_i, base) for base_inds_i in base_inds]
return base_vecs 

Example 4

def sampleSize(self):
r = 0.3
alpha = 0.05
#        power=0.9

C = 0.5 * np.log((1 + r) / (1 - r))

Za = scipy.stats.norm.ppf(1 - (0.05 / 2))

sizeArray = []
powerArray = []

power = 0.5
for i in range(50, 100, 1):
power = i / 100
powerArray.append(power)

Zb = scipy.stats.norm.ppf(1 - power)
N = abs((Za - Zb) / C)**2 + 3

sizeArray.append(N)

return [powerArray, sizeArray] 

Example 5

def sample(self, sample_size=20, text=None):
"""Sample the documents."""
p = 1

if text != None:
try:
except Exception as e:
print(e)
return
else:
print(" [*] Text: %s" % " ".join([self.reader.idx2word[word_idx] for word_idx in word_idxs]))

cur_ps = self.sess.run(self.p_x_i, feed_dict={self.x: x})
word_idxs = np.array(cur_ps).argsort()[-sample_size:][::-1]
ps = cur_ps[word_idxs]

for idx, (cur_p, word_idx) in enumerate(zip(ps, word_idxs)):
print("  [%d] %-20s: %.8f" % (idx+1, self.reader.idx2word[word_idx], cur_p))
p *= cur_p

print(" [*] perp : %8.f" % -np.log(p)) 

Example 6

def lr_grad_norm_avg(self):
# this is for enforcing lr * grad_norm not
# increasing dramatically in case of instability.
#  Not necessary for basic use.
global_state = self._global_state
beta = self._beta
+ (1 - beta) * np.log(global_state['grad_norm_squared'] + eps)
0.0 * beta + (1 - beta) * np.log(self._lr * np.sqrt(global_state['grad_norm_squared'] ) + eps)
# we monitor the minimal smoothed ||lr * grad||
else:
+ (1 - beta) * np.log(self._lr * np.sqrt(global_state['grad_norm_squared'] ) + eps)
np.exp(global_state["lr_grad_norm_avg"] / self.zero_debias_factor() ) ) 

Example 7

def lr_grad_norm_avg(self):
# this is for enforcing lr * grad_norm not
# increasing dramatically in case of instability.
#  Not necessary for basic use.
global_state = self._global_state
beta = self._beta
+ (1 - beta) * np.log(global_state['grad_norm_squared'] + eps)
0.0 * beta + (1 - beta) * np.log(self._lr * np.sqrt(global_state['grad_norm_squared'] ) + eps)
# we monitor the minimal smoothed ||lr * grad||
else:
+ (1 - beta) * np.log(self._lr * np.sqrt(global_state['grad_norm_squared'] ) + eps)
np.exp(global_state["lr_grad_norm_avg"] / self.zero_debias_factor() ) ) 

Example 8

def sample_dtype(self):
return tf.int32

# WRONG SECOND DERIVATIVES
# class CategoricalPd(Pd):
#     def __init__(self, logits):
#         self.logits = logits
#         self.ps = tf.nn.softmax(logits)
#     @classmethod
#     def fromflat(cls, flat):
#         return cls(flat)
#     def flatparam(self):
#         return self.logits
#     def mode(self):
#         return U.argmax(self.logits, axis=1)
#     def logp(self, x):
#         return -tf.nn.sparse_softmax_cross_entropy_with_logits(self.logits, x)
#     def kl(self, other):
#         return tf.nn.softmax_cross_entropy_with_logits(other.logits, self.ps) \
#                 - tf.nn.softmax_cross_entropy_with_logits(self.logits, self.ps)
#     def entropy(self):
#         return tf.nn.softmax_cross_entropy_with_logits(self.logits, self.ps)
#     def sample(self):
#         u = tf.random_uniform(tf.shape(self.logits))
#         return U.argmax(self.logits - tf.log(-tf.log(u)), axis=1) 

Example 9

def spec_entropy(Rates,time_range=[],bin_w = 5.,freq_range = []):
'''Function to calculate the spectral entropy'''

power,freq,dfreq,dummy,dummy = mypsd(Rates,time_range,bin_w = bin_w)
if freq_range != []:
power = power[(freq>=freq_range[0]) & (freq <= freq_range[1])]
freq = freq[(freq>=freq_range[0]) & (freq <= freq_range[1])]
maxFreq = freq[np.where(power==np.max(power))]*1000*100
perMax = (np.max(power)/np.sum(power))*100
k = len(freq)
power = power/sum(power)
sum_power = 0
for ii in range(k):
sum_power += (power[ii]*np.log(power[ii]))
spec_ent = -(sum_power/np.log(k))
return spec_ent,dfreq,maxFreq,perMax 

Example 10

def __init__(self, nlp, **kwargs):
"""
Initializes a new instance of SpacySimilarityHook class.

:param nlp: spaCy language object <https://spacy.io/docs/api/language>_.
:param ignore_stops: Indicates whether to ignore the stop words.
:param only_alpha: Indicates whether only alpha tokens must be used.
:param frequency_processor: The function which is applied to raw \
token frequencies.
:type ignore_stops: bool
:type only_alpha: bool
:type frequency_processor: callable
"""
self.nlp = nlp
self.ignore_stops = kwargs.get("ignore_stops", True)
self.only_alpha = kwargs.get("only_alpha", True)
self.frequency_processor = kwargs.get(
"frequency_processor", lambda t, f: numpy.log(1 + f)) 

Example 11

def gaussian_nll(x, mus, sigmas):
"""
NLL for Multivariate Normal with diagonal covariance matrix
See:
wikipedia.org/wiki/Multivariate_normal_distribution#Likelihood_function
where \Sigma = diag(s_1^2,..., s_n^2).

x, mus, sigmas all should have the same shape.
sigmas (s_1,..., s_n) should be strictly positive.
Results in output shape of similar but without the last dimension.
"""
nll = lib.floatX(numpy.log(2. * numpy.pi))
nll += 2. * T.log(sigmas)
nll += ((x - mus) / sigmas) ** 2.
nll = nll.sum(axis=-1)
nll *= lib.floatX(0.5)
return nll 

Example 12

def monotoneTFosc(f):
"""Maps [-inf,inf] to [-inf,inf] with different constants
for positive and negative part.

"""
if np.isscalar(f):
if f > 0.:
f = np.log(f) / 0.1
f = np.exp(f + 0.49 * (np.sin(f) + np.sin(0.79 * f))) ** 0.1
elif f < 0.:
f = np.log(-f) / 0.1
f = -np.exp(f + 0.49 * (np.sin(0.55 * f) + np.sin(0.31 * f))) ** 0.1
return f
else:
f = np.asarray(f)
g = f.copy()
idx = (f > 0)
g[idx] = np.log(f[idx]) / 0.1
g[idx] = np.exp(g[idx] + 0.49 * (np.sin(g[idx]) + np.sin(0.79 * g[idx])))**0.1
idx = (f < 0)
g[idx] = np.log(-f[idx]) / 0.1
g[idx] = -np.exp(g[idx] + 0.49 * (np.sin(0.55 * g[idx]) + np.sin(0.31 * g[idx])))**0.1
return g 

Example 13

def logscale_img(img_array,
cap=255.0,
coeff=1000.0):
'''
This scales the image according to the relation:

logscale_img = np.log(coeff*(img/max(img))+1)/np.log(coeff)

Taken from the DS9 scaling algorithms page at:

http://hea-www.harvard.edu/RD/ds9/ref/how.html

According to that page:

coeff = 1000.0 works well for optical images
coeff = 100.0 works well for IR images

'''

logscaled_img = np.log(coeff*img_array/np.nanmax(img_array)+1)/np.log(coeff)
return cap*logscaled_img 

Example 14

def forward(self, outputs, targets):
"""SoftmaxCategoricalCrossEntropy forward propagation.

.. math:: L_i = - \\sum_j{t_{i,j} \\log(p_{i,j})}

Parameters
----------
outputs : numpy.array
Predictions in (0, 1), such as softmax output of a neural network,
with data points in rows and class probabilities in columns.
targets : numpy.array
Either targets in [0, 1] matching the layout of outputs, or
a vector of int giving the correct class index per data point.

Returns
-------
numpy 1D array
An expression for the item-wise categorical cross-entropy.
"""
outputs = np.clip(outputs, self.epsilon, 1 - self.epsilon)
return np.mean(-np.sum(targets * np.log(outputs), axis=1)) 

Example 15

def test_GWD(self):
# Compute categorical crossentropy
indices = self.mock_y > 0
selected_log = -np.log(self.mock_x_softmax[indices])
self.loss = 0#np.sum(selected_log) / np.sum(self.mock_y)
# Create keras model with this activation and compile it
model = Sequential()
activation_layer = Lambda(lambda x: x,
input_shape=self.data_shape[1:],
output_shape=self.data_shape[1:]
)
model.compile('sgd', loss=gwd)

# Predict data from the model
loss = model.evaluate(self.mock_y, self.mock_y, batch_size=1, verbose=0)
# Assertions
print('Expected loss: {}'.format(self.loss))
print('Actual loss: {}'.format(loss))
self.assertTrue(np.allclose(loss, self.loss),
msg='Categorical cross-entropy loss 3D does not produce the expected results') 

Example 16

def logTickValues(self, minVal, maxVal, size, stdTicks):

## Any level whose spacing is < 1 needs to be converted to log scale

ticks = []
for (spacing, t) in stdTicks:
if spacing >= 1.0:
ticks.append((spacing, t))

if len(ticks) < 3:
v1 = int(np.floor(minVal))
v2 = int(np.ceil(maxVal))
#major = list(range(v1+1, v2))

minor = []
for v in range(v1, v2):
minor.extend(v + np.log10(np.arange(1, 10)))
minor = [x for x in minor if x>minVal and x<maxVal]
ticks.append((None, minor))
return ticks 

Example 17

def logTickValues(self, minVal, maxVal, size, stdTicks):

## Any level whose spacing is < 1 needs to be converted to log scale

ticks = []
for (spacing, t) in stdTicks:
if spacing >= 1.0:
ticks.append((spacing, t))

if len(ticks) < 3:
v1 = int(np.floor(minVal))
v2 = int(np.ceil(maxVal))
#major = list(range(v1+1, v2))

minor = []
for v in range(v1, v2):
minor.extend(v + np.log10(np.arange(1, 10)))
minor = [x for x in minor if x>minVal and x<maxVal]
ticks.append((None, minor))
return ticks 

Example 18

def summary(self):
s = OrderedDict()
s['source kind'] = self.sourcekind
s['source'] = self.source
if self.params is not None:
for param, value in self.params._asdict().items():
s['parameter: %s' % param] = value
s['log-variance theoretical half-life'] = self.params.logvarhalflife()
s['log-variance theoretical unconditional s.d.'] = np.sqrt(self.params.logvaruncondvar())
s['log-return sample mean'] = np.mean(self.svdf['logreturn'])
s['log-return sample s.d.'] = np.sqrt(np.var(self.svdf['logreturn']))
if 'logvar' in self.svdf.columns:
s['log-variance sample mean'] = np.mean(self.svdf['logvar'])
s['log-variance sample s.d.'] = np.sqrt(np.var(self.svdf['logvar']))
s['correlation timing'] = self.cortiming
s['log-return forward?'] = self.logreturnforward
s['log-return scale'] = self.logreturnscale
return s 

Example 19

def multiclass_log_loss(y_true, y_pred, eps=1e-15):
"""Multi class version of Logarithmic Loss metric.
https://www.kaggle.com/wiki/MultiClassLogLoss
Parameters
----------
y_true : array, shape = [n_samples]
true class, intergers in [0, n_classes - 1)
y_pred : array, shape = [n_samples, n_classes]
Returns
-------
loss : float
"""
predictions = np.clip(y_pred, eps, 1 - eps)

# normalize row sums to 1
predictions /= predictions.sum(axis=1)[:, np.newaxis]

actual = np.zeros(y_pred.shape)
n_samples = actual.shape[0]
actual[np.arange(n_samples), y_true.astype(int)] = 1
vectsum = np.sum(actual * np.log(predictions))
loss = -1.0 / n_samples * vectsum
return loss 

Example 20

def step(self, mode):
if mode == "train" and self.mode == "test":
raise Exception("Cannot train during test mode")

if mode == "train":
theano_fn = self.train_fn
batch_gen = self.train_batch_gen
elif mode == "test":
theano_fn = self.test_fn
batch_gen = self.test_batch_gen
else:
raise Exception("Invalid mode")

data = next(batch_gen)
ys = data[-1]
data = data[:-1]
ret = theano_fn(*data)

return {"prediction": np.exp(ret[0]) - 1,
"current_loss": ret[1],
"loss_reg": ret[2],
"loss_mse": ret[1] - ret[2],
"log": ""} 

Example 21

def evaluation(self, X_test, y_test):
# normalization
X_test = self.normalization(X_test)

# average over the output
pred_y_test = np.zeros([self.M, len(y_test)])
prob = np.zeros([self.M, len(y_test)])

'''
Since we have M particles, we use a Bayesian view to calculate rmse and log-likelihood
'''
for i in range(self.M):
w1, b1, w2, b2, loggamma, loglambda = self.unpack_weights(self.theta[i, :])
pred_y_test[i, :] = self.nn_predict(X_test, w1, b1, w2, b2) * self.std_y_train + self.mean_y_train
prob[i, :] = np.sqrt(np.exp(loggamma)) /np.sqrt(2*np.pi) * np.exp( -1 * (np.power(pred_y_test[i, :] - y_test, 2) / 2) * np.exp(loggamma) )
pred = np.mean(pred_y_test, axis=0)

# evaluation
svgd_rmse = np.sqrt(np.mean((pred - y_test)**2))
svgd_ll = np.mean(np.log(np.mean(prob, axis = 0)))

return (svgd_rmse, svgd_ll) 

Example 22

def sample(self, sess, chars, vocab, num, prime, temperature):
state = self.cell.zero_state(1, tf.float32).eval()
for char in prime[:-1]:
x = np.zeros((1, 1))
x[0, 0] = vocab[char]
feed = {self.input_data: x, self.initial_state: state}
[state] = sess.run([self.final_state], feed)

def weighted_pick(a):
a = a.astype(np.float64)
a = a.clip(min=1e-20)
a = np.log(a) / temperature
a = np.exp(a) / (np.sum(np.exp(a)))
return np.argmax(np.random.multinomial(1, a, 1))

char = prime[-1]
for n in range(num):
x = np.zeros((1, 1))
x[0, 0] = vocab[char]
feed = {self.input_data: x, self.initial_state: state}
[probs, state] = sess.run([self.probs, self.final_state], feed)
p = probs[0]
sample = weighted_pick(p)
char = chars[sample]
yield char 

Example 23

def update_qz(self, left = None, right = None):

if left == None:
left = 0
right = self.lc.n

for index in range(left, right):
#if index % 100 == 0:
#    print index
#    sys.stdout.flush()

qz_1 = np.log(self.theta)
qz_0 = np.log(1 - self.theta)
for (label, worker) in zip(*self.lc.crowd_labels[index]):
if label >=0 and worker in self.quv:
qz_1 += expectation_z(self.quv[worker][0], self.quv[worker][1], label)
qz_0 += expectation_z(self.quv[worker][2], self.quv[worker][3], label)

qz_1 = np.exp(qz_1)
qz_0 = np.exp(qz_0)

temp = qz_1 * 1.0 / (qz_0 + qz_1)
if not math.isnan(temp):
self.total_changes += np.abs(self.qz[index] - temp)
self.qz[index] = temp 

Example 24

def fit_normal(self, a):
"""
fit a normal distribution to [(x, p)]
where p is in log scale
"""
# normalize p:
#print a
list_p = []
for (x, p) in a:  list_p.append(p)
ps = scipy.misc.logsumexp(list_p)

s  = 0
ss = 0
for (x, p) in a:
s  += x * np.exp(p - ps)
ss += x*x * np.exp(p - ps)

var = ss - s*s
ep = 1E-300
if var < ep: var = ep
return (s, var) 

Example 25

def eval_pdf(self, worker, var, x, list_il):
"""
Eval *LOG* of pdf of new qu or qv
"""
if var == 'sen':
res = expectation_binorm('v', self.quv[worker][2], self.quv[worker][3], \
x, self.get_mu(worker), self.get_c(worker))
#print res
for (item, label) in list_il:
item_w = self.get_item_w(item)
res += item_w * self.qz[item] * np.log( self.Ber(S(x), label))
else:
res = expectation_binorm('u', self.quv[worker][0], self.quv[worker][1], \
x, self.get_mu(worker), self.get_c(worker))
for (item, label) in list_il:
item_w = self.get_item_w(item)
res += item_w * (1 - self.qz[item]) * np.log( self.Ber(S(x), label))

return res 

Example 26

def expectation_z(mu, var, L, w = 3):
"""
USE LAPLACE approx
Evaluate the expectation of log[ S(u)^L (1-S(u))^(1-L) ]
when u ~ Normal(mu, var)
"""
if L == 1:
f = lambda u: np.log(S(u))
fpp = lambda x: -np.exp(x) / pow(1 + np.exp(x), 2)
return f(mu) + 0.5* fpp(mu)*var
else:
f = lambda u: np.log(1 - S(u))
fpp = lambda x: -np.exp(x) / pow(1 + np.exp(x), 2)
return f(mu) + 0.5* fpp(mu)*var

# need: E[u~N](f)
return scipy.integrate.quad(f, mu - w*std, mu + w*std)[0] 

Example 27

def expectation_z_quad(mu, var, L, w = 3):
"""
Evaluate the expectation of log[ S(u)^L (1-S(u))^(1-L) ]
when u ~ Normal(mu, var)
"""
#U = np.random.normal(mu, np.sqrt(var), num)
if L == 1:
f = lambda u: scipy.stats.norm.pdf(u, loc = mu, scale = np.sqrt(var) ) * np.log(S(u))
else:
f = lambda u: scipy.stats.norm.pdf(u, loc = mu, scale = np.sqrt(var) ) * (np.log(1 - S(u)))

#return f
std = np.sqrt(var)
#return scipy.integrate.quad(f, mu - w*std, mu + w*std, epsabs = 1.0e-4, epsrel = 1.0e-4, limit = 25)[0]
return scipy.integrate.quad(f, mu - w*std, mu + w*std)[0] 

Example 28

def expectation_binorm(rv, mu, var, x, M, C, w = 3):
"""
Evaluate the expectation of log Norm(uv| M, C)
x = u, v ~ Norm(mu, var) rv == 'v'
x = v, u ~ Norm(mu, var) rv == 'u'
"""
#print rv, mu, var, x, M, C
if rv == 'v':
f = lambda v: scipy.stats.norm.pdf(v, loc = mu, scale = np.sqrt(var) ) * \
np.log(scipy.stats.multivariate_normal.pdf([x, v], mean = M, cov = C, allow_singular = True))
else:
f = lambda u: scipy.stats.norm.pdf(u, loc = mu, scale = np.sqrt(var) ) * \
np.log(scipy.stats.multivariate_normal.pdf([u, x], mean = M, cov = C, allow_singular = True))

#return f
#print f(mu)
std = np.sqrt(var)
return scipy.integrate.quad(f, mu - w*std, mu + w*std)[0] 

Example 29

def austerity(log_lik,log_density_prior, X,epsilon,batch_size=30,chain_size=10000, thinning=1, theta_t=np.random.randn()):
A = [theta_t]
N = X.shape[0]
dimension=1
if hasattr(theta_t, "__len__"):
dimension = len(theta_t)

global_evals = 0
for i in range(chain_size*thinning-1):
# if i % 1000 ==0:
#     print( 100.0*i/(chain_size*thinning), ' %')
theta_prime = np.random.randn(dimension)+theta_t

u = np.random.rand()
mu_0 = np.log(u)+log_density_prior(theta_t) -log_density_prior(theta_prime)
mu_0 = mu_0/N

accept,evals = approximate_MH_accept(mu_0, log_lik, X, batch_size, epsilon, theta_prime, theta_t, N)
global_evals += evals
if accept:
theta_t = theta_prime

A.append(theta_t)

return np.array(A[::thinning]),global_evals 

Example 30

def evaluate_stance(
self,
testN,
testtimes,
testinfecting_vec,
testinfected_vec,
testeventmemes,
testW,
testT,
):
predictednode_vec = []

for next_event_index in xrange(len(testtimes)):
print 'considering event', next_event_index
words = testW[next_event_index, :]

predictions = []
for label in set(self.node_vec):
loglikelihood_term = 0
loglikelihood_term += np.dot(words,
np.log(self.beta[label, :]))
predictions.append((label, loglikelihood_term))
predictednode_vec.append(max(predictions, key=lambda x: \
x[1])[0])
return predictednode_vec 

Example 31

def _beta_update_raw_tfidf(self):
'''
Run only once - it does not depend on other parameters.
'''

for nodeid in xrange(self.D):
self.beta[nodeid] = self.W[self.node_vec == nodeid, :
].sum(axis=0)
for nodeid in xrange(self.D):
for wordid in xrange(self.beta.shape[1]):
docs_cnt = np.sum(self.W[self.node_vec == nodeid,
wordid] >= 1)
docs_cnt += 1  # smooth by adding one
self.beta[nodeid][wordid] *= 1 + np.log(self.W.shape[0]
* 1. / docs_cnt)  # 1+ because we still want to keep words which always occurr, but probably it never happens

# Laplace smoothing to avoid zeros!

self.beta += 1
self._normalize_beta_rowwise()
return self.beta 

Example 32

def b_value(mags, mt, perc=[2.5, 97.5], n_reps=None):
"""Compute the b-value and optionally its confidence interval."""
# Extract magnitudes above completeness threshold
m = mags[mags >= mt]

# Compute b-value
b = (np.mean(m) - mt) * np.log(10)

# Draw bootstrap replicates
if n_reps is None:
return b
else:
m_bs_reps = dcst.draw_bs_reps(m, np.mean, size=n_reps)

# Compute b-value from replicates
b_bs_reps = (m_bs_reps - mt) * np.log(10)

# Compute confidence interval
conf_int = np.percentile(b_bs_reps, perc)

return b, conf_int 

Example 33

def f(w, lamb):
"""
Eq. (2) in problem 2

Non-vectorized, slow
"""
total = 0
nrows = X.shape[0]
for i in range(nrows):
current = 1 + np.exp(-y[i] * X[i, ].dot(w))
total += np.log(current)
total += (lamb / 2) * w.dot(w)
return total 

Example 34

def f2(w, lamb):
"""
Eq. (2) in problem 2

Vectorized (no explicit loops), fast
"""
yxTw = y * X.dot(w)
firstpart = np.log(1 + np.exp(-yxTw))
total = firstpart.sum()
total += (lamb / 2) * w.dot(w)
return total 

Example 35

def pac_metric (solution, prediction, task='binary.classification'):
''' Probabilistic Accuracy based on log_loss metric.
We assume the solution is in {0, 1} and prediction in [0, 1].
Otherwise, run normalize_array.'''
debug_flag=False
[sample_num, label_num] = solution.shape
eps = 1e-15
# Compute the base log loss (using the prior probabilities)
pos_num = 1.* sum(solution) # float conversion!
frac_pos = pos_num / sample_num # prior proba of positive class
# Alternative computation of the same thing (slower)
# Should always return the same thing except in the multi-label case
# For which the analytic solution makes more sense
if debug_flag:
base_prediction = np.empty(prediction.shape)
for k in range(sample_num): base_prediction[k,:] = frac_pos
diff = np.array(abs(the_base_log_loss-base_log_loss))
if len(diff.shape)>0: diff=max(diff)
if(diff)>1e-10:
print('Arrggh {} != {}'.format(the_base_log_loss,base_log_loss))
# Exponentiate to turn into an accuracy-like score.
# In the multi-label case, we need to average AFTER taking the exp
# because it is an NL operation
pac = mvmean(np.exp(-the_log_loss))
base_pac = mvmean(np.exp(-the_base_log_loss))
# Normalize: 0 for random, 1 for perfect
score = (pac - base_pac) / sp.maximum(eps, (1 - base_pac))
return score 

Example 36

def log_loss(solution, prediction, task = 'binary.classification'):
''' Log loss for binary and multiclass. '''
[sample_num, label_num] = solution.shape
eps = 1e-15

pred = np.copy(prediction) # beware: changes in prediction occur through this
sol = np.copy(solution)
if (task == 'multiclass.classification') and (label_num>1):
# Make sure the lines add up to one for multi-class classification
norma = np.sum(prediction, axis=1)
for k in range(sample_num):
pred[k,:] /= sp.maximum (norma[k], eps)
# Make sure there is a single label active per line for multi-class classification
# For the base prediction, this solution is ridiculous in the multi-label case

# Bounding of predictions to avoid log(0),1/0,...
pred = sp.minimum (1-eps, sp.maximum (eps, pred))
# Compute the log loss
pos_class_log_loss = - mvmean(sol*np.log(pred), axis=0)
if (task != 'multiclass.classification') or (label_num==1):
# The multi-label case is a bunch of binary problems.
# The second class is the negative class for each column.
neg_class_log_loss = - mvmean((1-sol)*np.log(1-pred), axis=0)
log_loss = pos_class_log_loss + neg_class_log_loss
# Each column is an independent problem, so we average.
# The probabilities in one line do not add up to one.
# log_loss = mvmean(log_loss)
# print('binary {}'.format(log_loss))
# In the multilabel case, the right thing i to AVERAGE not sum
# We return all the scores so we can normalize correctly later on
else:
# For the multiclass case the probabilities in one line add up one.
log_loss = pos_class_log_loss
# We sum the contributions of the columns.
log_loss = np.sum(log_loss)
#print('multiclass {}'.format(log_loss))
return log_loss 

Example 37

def prior_log_loss(frac_pos, task = 'binary.classification'):
''' Baseline log loss. For multiplr classes ot labels return the volues for each column'''
eps = 1e-15
frac_pos_ = sp.maximum (eps, frac_pos)
if (task != 'multiclass.classification'): # binary case
frac_neg = 1-frac_pos
frac_neg_ = sp.maximum (eps, frac_neg)
pos_class_log_loss_ = - frac_pos * np.log(frac_pos_)
neg_class_log_loss_ = - frac_neg * np.log(frac_neg_)
base_log_loss = pos_class_log_loss_ + neg_class_log_loss_
# base_log_loss = mvmean(base_log_loss)
# print('binary {}'.format(base_log_loss))
# In the multilabel case, the right thing i to AVERAGE not sum
# We return all the scores so we can normalize correctly later on
else: # multiclass case
fp = frac_pos_ / sum(frac_pos_) # Need to renormalize the lines in multiclass case
# Only ONE label is 1 in the multiclass case active for each line
pos_class_log_loss_ = - frac_pos * np.log(fp)
base_log_loss = np.sum(pos_class_log_loss_)
return base_log_loss

# sklearn implementations for comparison 

Example 38

def sample(self, probs, temperature):
if temperature == 0:
return np.argmax(probs)

probs = probs.astype(np.float64) #convert to float64 for higher precision
probs = np.log(probs) / temperature
probs = np.exp(probs) / math.fsum(np.exp(probs))
return np.argmax(np.random.multinomial(1, probs, 1))

#generate a sentence given conv_hidden 

Example 39

def test(self, vocab_size, use_onto_lstm, S_ind_test=None, C_ind_test=None, hierarchical=False, base=2, oov_list=None):
X_test = C_ind_test[:,:-1] if use_onto_lstm else S_ind_test[:,:-1] # remove the last words' hyps in all sentences
Y_inds_test = S_ind_test[:,1:]
if hierarchical:
test_targets = self._factor_target_indices(Y_inds_test, vocab_size, base=base)
else:
test_targets = [self._make_one_hot(Y_inds_test, vocab_size)]
print >>sys.stderr, "Evaluating model on test data"
test_loss = self.model.evaluate(X_test, test_targets)
print >>sys.stderr, "Test loss: %.4f"%test_loss
if oov_list is not None:
oov_inds = [self.dp.word_index[w] for w in oov_list]
non_oov_Y_inds = numpy.copy(Y_inds_test)
for ind in oov_inds:
non_oov_Y_inds[non_oov_Y_inds == ind] = 0
non_oov_test_targets = self._factor_target_indices(non_oov_Y_inds, vocab_size, base=base)
non_oov_test_loss = self.model.evaluate(X_test, non_oov_test_targets)
print >>sys.stderr, "Non-oov test loss: %.4f"%non_oov_test_loss
factored_test_preds = [-((numpy.log(pred) * target).sum(axis=-1)) for pred, target in zip(self.model.predict(X_test), test_targets)]
test_preds = sum(factored_test_preds)
#non_null_probs = []
#for test_pred, inds in zip(test_preds, Y_inds_test):
#  wanted_probs = []
#  for tp, ind in zip(test_pred, inds):
#    if ind != 0:
#      wanted_probs.append(tp)
#  non_null_probs.append(wanted_probs)
#return non_null_probs
return test_preds 

Example 40

def data_log_likelihood(self, dataSplit, coefficients, variances):

log_likelihood = 0.0

for k in range(self.num_components):

coef_ = coefficients[k]

Beta = coef_.ix[self.endoVar][self.endoVar]
Gamma = coef_.ix[self.endoVar][self.exoVar]

a_ = (np.dot(Beta, self.fscores[
self.endoVar].T) + np.dot(Gamma, self.fscores[self.exoVar].T))

invert_ = np.linalg.inv(np.array(variances[k]))

exponential = np.exp(-0.5 * np.dot(np.dot(a_.T, invert_), a_))

den = (((2 * np.pi)**(self.Q / 2)) *
np.sqrt(np.linalg.det(variances[k])))
probabilities = exponential[0] / den

log_likelihood += np.log(probabilities).sum()

print(log_likelihood)
return log_likelihood 

Example 41

def BTS(data):

n = data.shape[0]
p = data.shape[1]

chi2 = -(n - 1 - (2 * p + 5) / 6) * \
np.log(np.linalg.det(pd.DataFrame.corr(data)))
df = p * (p - 1) / 2

pvalue = scipy.stats.distributions.chi2.sf(chi2, df)

return [chi2, pvalue] 

Example 42

def build_model(self):
self.x_idx = tf.placeholder(tf.int32, [None], name="x_idx")

self.build_encoder()
self.build_generator()

# Kullback Leibler divergence
self.e_loss = -0.5 * tf.reduce_sum(1 + self.log_sigma_sq - tf.square(self.mu) - tf.exp(self.log_sigma_sq))

# Log likelihood
self.g_loss = -tf.reduce_sum(tf.log(tf.gather(self.p_x_i, self.x_idx) + 1e-10))

self.loss = self.e_loss + self.g_loss

self.encoder_var_list, self.generator_var_list = [], []
for var in tf.trainable_variables():
if "encoder" in var.name:
self.encoder_var_list.append(var)
elif "generator" in var.name:
self.generator_var_list.append(var)

# optimizer for alternative update
.minimize(self.e_loss, global_step=self.step, var_list=self.encoder_var_list)
.minimize(self.g_loss, global_step=self.step, var_list=self.generator_var_list)

# optimizer for one shot update
.minimize(self.loss, global_step=self.step)

_ = tf.scalar_summary("encoder loss", self.e_loss)
_ = tf.scalar_summary("generator loss", self.g_loss)
_ = tf.scalar_summary("total loss", self.loss) 

Example 43

def edge_logits(self):
"""Get edge log probabilities on the complete graph.""" 

Example 44

def logprob(self, data):
"""Compute non-normalized log probabilies of many rows of data.""" 

Example 45

def logprob(self, data):
logprobs = np.stack(
[server.logprob(data) for server in self._ensemble])
logprobs = logsumexp(logprobs, axis=0)
logprobs -= np.log(len(self._ensemble))
assert logprobs.shape == (data.shape[0], )
return logprobs 

Example 46

def edge_logits(self):
"""A [K]-shaped array of log odds of edges in the complete graph."""
return self._server.edge_logits 

Example 47

def make_model_path(name):
log_path = os.path.join('log', name)
if os.path.isdir(log_path):
subprocess.call(('rm -rf %s' % log_path).split())
os.makedirs(log_path)
return log_path 

Example 48

def compute_log_sum(val):
min_val = np.min(val, axis=0, keepdims=True)
return np.mean(min_val - np.log(np.mean(np.exp(-val + min_val), axis=0))) 

Example 49

def getInitialHyps(self, X, C, y):
self.logdetXX  = np.linalg.slogdet(C.T.dot(C))[1]

hyp0_sig2e = [0.5*np.log(0.5*y.var())]
Linreg = sklearn.linear_model.LinearRegression(fit_intercept=False, normalize=False, copy_X=False)
Linreg.fit(C, y)
hyp0_fixedEffects = Linreg.coef_
return hyp0_sig2e, hyp0_fixedEffects 

Example 50

def rankRegions(self, X, C, y, pos, regionLength, reml=True):

#get resiong list
regionsList = self.createRegionsList(pos, regionLength)

#precompute log determinant of covariates
XX = C.T.dot(C)
[Sxx,Uxx]= la.eigh(XX)
logdetXX  = np.log(Sxx).sum()

#score each region
betas = np.zeros(len(regionsList))
for r_i, r in enumerate(regionsList):
regionSize = len(r)

if (self.verbose and r_i % 1000==0):
print 'Testing region ' + str(r_i+1)+'/'+str(len(regionsList)),
print 'with', regionSize, 'SNPs\t'

s,U = self.eigenDecompose(X[:, np.array(r)], None)
sig2g_kernel, sig2e_kernel, fixedEffects, ll = self.optSigma2(U, s, y, C, logdetXX, reml)
betas[r_i] = ll

return regionsList, betas

### this code is taken from the FastLMM package (see attached license)###