ottertune/server/analysis/gp_tf.py

771 lines
31 KiB
Python

#
# OtterTune - gp_tf.py
#
# Copyright (c) 2017-18, Carnegie Mellon University Database Group
#
'''
Created on Aug 18, 2016
@author: Bohan Zhang, Dana Van Aken
'''
import gc
import numpy as np
import tensorflow as tf
from .util import get_analysis_logger
LOG = get_analysis_logger(__name__)
class GPRResult(object):
def __init__(self, ypreds=None, sigmas=None):
self.ypreds = ypreds
self.sigmas = sigmas
class GPRGDResult(GPRResult):
def __init__(self, ypreds=None, sigmas=None,
minl=None, minl_conf=None):
super(GPRGDResult, self).__init__(ypreds, sigmas)
self.minl = minl
self.minl_conf = minl_conf
class GPR(object):
def __init__(self, length_scale=2.0, magnitude=1.0, ridge=1.0, max_train_size=7000,
batch_size=3000, num_threads=4, check_numerics=True, debug=False,
hyperparameter_trainable=False):
assert np.isscalar(length_scale)
assert np.isscalar(magnitude)
assert length_scale > 0 and magnitude > 0
self.length_scale = length_scale
self.magnitude = magnitude
self.ridge = ridge
self.max_train_size_ = max_train_size
self.batch_size_ = batch_size
self.num_threads_ = num_threads
self.check_numerics = check_numerics
self.debug = debug
self.hyperparameter_trainable = hyperparameter_trainable
self.X_train = None
self.y_train = None
self.xy_ = None
self.K = None
self.K_inv = None
self.graph = None
self.vars = None
self.ops = None
def build_graph(self):
self.vars = {}
self.ops = {}
self.graph = tf.Graph()
with self.graph.as_default():
if self.hyperparameter_trainable:
r"""
A transform of the form
.. math::
y = \log(1 + \exp(x))
x is a free variable, y is always positive.
This function is known as 'softplus' in tensorflow.
This transformation gaurantees y value is always positive
"""
mag_ = np.log(np.exp(self.magnitude) - 1)
ls_ = np.log(np.exp(self.length_scale) - 1)
noise_ = np.log(np.exp(self.ridge) - 1)
mag_var = tf.nn.softplus(tf.Variable(mag_,
dtype=np.float32,
name='magnitude'))
ls_var = tf.nn.softplus(tf.Variable(ls_,
dtype=np.float32,
name='length_scale'))
noise_var = tf.nn.softplus(tf.Variable(noise_,
dtype=np.float32,
name='noise_scale'))
else:
mag_var = tf.constant(self.magnitude,
dtype=np.float32,
name='magnitude')
ls_var = tf.constant(self.length_scale,
dtype=np.float32,
name='length_scale')
noise_var = tf.constant(self.ridge,
dtype=np.float32,
name='noise_scale')
# Nodes for distance computation
v1 = tf.placeholder(tf.float32, name="v1")
v2 = tf.placeholder(tf.float32, name="v2")
dist_op = tf.sqrt(tf.reduce_sum(tf.pow(tf.subtract(v1, v2), 2), 1), name='dist_op')
if self.check_numerics:
dist_op = tf.check_numerics(dist_op, "dist_op: ")
self.vars['v1_h'] = v1
self.vars['v2_h'] = v2
self.ops['dist_op'] = dist_op
self.vars['mag_v'] = mag_var
self.vars['ls_v'] = ls_var
self.vars['noise_v'] = noise_var
# Nodes for kernel computation
X_dists = tf.placeholder(tf.float32, name='X_dists')
ridge_ph = tf.placeholder(tf.float32, name='ridge')
K_op = mag_var * tf.exp(-X_dists / ls_var) # pylint: disable=invalid-name
if self.check_numerics:
K_op = tf.check_numerics(K_op, "K_op: ")
K_ridge_op = K_op + tf.diag(ridge_ph)
if self.check_numerics:
K_ridge_op = tf.check_numerics(K_ridge_op, "K_ridge_op: ")
self.vars['X_dists_h'] = X_dists
self.vars['ridge_h'] = ridge_ph
self.ops['K_op'] = K_op
self.ops['K_ridge_op'] = K_ridge_op
# Nodes for xy computation
K = tf.placeholder(tf.float32, name='K')
K_inv = tf.placeholder(tf.float32, name='K_inv')
xy_ = tf.placeholder(tf.float32, name='xy_')
yt_ = tf.placeholder(tf.float32, name='yt_')
K_inv_op = tf.matrix_inverse(K)
if self.check_numerics:
K_inv_op = tf.check_numerics(K_inv_op, "K_inv: ")
xy_op = tf.matmul(K_inv, yt_)
if self.check_numerics:
xy_op = tf.check_numerics(xy_op, "xy_: ")
self.vars['K_h'] = K
self.vars['K_inv_h'] = K_inv
self.vars['xy_h'] = xy_
self.vars['yt_h'] = yt_
self.ops['K_inv_op'] = K_inv_op
self.ops['xy_op'] = xy_op
# Nodes for yhat/sigma computation
K2 = tf.placeholder(tf.float32, name="K2")
K3 = tf.placeholder(tf.float32, name="K3")
ridge_test_ph = tf.placeholder(tf.float32, name="ridge_test_ph")
yhat_ = tf.cast(tf.matmul(tf.transpose(K2), xy_), tf.float32)
if self.check_numerics:
yhat_ = tf.check_numerics(yhat_, "yhat_: ")
sv1 = tf.matmul(tf.transpose(K2), tf.matmul(K_inv, K2))
if self.check_numerics:
sv1 = tf.check_numerics(sv1, "sv1: ")
sig_val = tf.cast((tf.sqrt(tf.diag_part(K3 + tf.diag(ridge_test_ph) - sv1))),
tf.float32)
if self.check_numerics:
sig_val = tf.check_numerics(sig_val, "sig_val: ")
self.vars['K2_h'] = K2
self.vars['K3_h'] = K3
self.ops['yhat_op'] = yhat_
self.ops['sig_op'] = sig_val
self.ops['ridge_test_h'] = ridge_test_ph
# Compute y_best (min y)
y_best_op = tf.cast(tf.reduce_min(yt_, 0, True), tf.float32)
if self.check_numerics:
y_best_op = tf.check_numerics(y_best_op, "y_best_op: ")
self.ops['y_best_op'] = y_best_op
sigma = tf.placeholder(tf.float32, name='sigma')
yhat = tf.placeholder(tf.float32, name='yhat')
self.vars['sigma_h'] = sigma
self.vars['yhat_h'] = yhat
def __repr__(self):
rep = ""
for k, v in sorted(self.__dict__.items()):
rep += "{} = {}\n".format(k, v)
return rep
def __str__(self):
return self.__repr__()
def check_X_y(self, X, y):
from sklearn.utils.validation import check_X_y
if X.shape[0] > self.max_train_size_:
raise Exception("X_train size cannot exceed {} ({})"
.format(self.max_train_size_, X.shape[0]))
return check_X_y(X, y, multi_output=True,
allow_nd=True, y_numeric=True,
estimator="GPR")
def check_fitted(self):
if self.X_train is None or self.y_train is None \
or self.xy_ is None or self.K is None:
raise Exception("The model must be trained before making predictions!")
@staticmethod
def check_array(X):
from sklearn.utils.validation import check_array
return check_array(X, allow_nd=True, estimator="GPR")
@staticmethod
def check_output(X):
finite_els = np.isfinite(X)
if not np.all(finite_els):
raise Exception("Input contains non-finite values: {}"
.format(X[~finite_els]))
def fit(self, X_train, y_train):
self._reset()
X_train, y_train = self.check_X_y(X_train, y_train)
self.X_train = np.float32(X_train)
self.y_train = np.float32(y_train)
sample_size = self.X_train.shape[0]
ridge = self.ridge
X_dists = np.zeros((sample_size, sample_size), dtype=np.float32)
with tf.Session(graph=self.graph,
config=tf.ConfigProto(
intra_op_parallelism_threads=self.num_threads_)) as sess:
init = tf.global_variables_initializer()
sess.run(init)
noise_var = self.vars['noise_v']
if np.isscalar(ridge):
ridge = np.ones(sample_size) * sess.run(noise_var)
assert isinstance(ridge, np.ndarray)
assert ridge.ndim == 1
dist_op = self.ops['dist_op']
v1, v2 = self.vars['v1_h'], self.vars['v2_h']
for i in range(sample_size):
X_dists[i] = sess.run(dist_op, feed_dict={v1: self.X_train[i], v2: self.X_train})
K_ridge_op = self.ops['K_ridge_op']
X_dists_ph = self.vars['X_dists_h']
ridge_ph = self.vars['ridge_h']
self.K = sess.run(K_ridge_op, feed_dict={X_dists_ph: X_dists, ridge_ph: ridge})
K_ph = self.vars['K_h']
K_inv_op = self.ops['K_inv_op']
self.K_inv = sess.run(K_inv_op, feed_dict={K_ph: self.K})
xy_op = self.ops['xy_op']
K_inv_ph = self.vars['K_inv_h']
yt_ph = self.vars['yt_h']
self.xy_ = sess.run(xy_op, feed_dict={K_inv_ph: self.K_inv,
yt_ph: self.y_train})
return self
def predict(self, X_test):
self.check_fitted()
X_test = np.float32(GPR.check_array(X_test))
test_size = X_test.shape[0]
sample_size = self.X_train.shape[0]
ridge = self.ridge
arr_offset = 0
yhats = np.zeros([test_size, 1])
sigmas = np.zeros([test_size, 1])
with tf.Session(graph=self.graph,
config=tf.ConfigProto(
intra_op_parallelism_threads=self.num_threads_)) as sess:
init = tf.global_variables_initializer()
sess.run(init)
noise_var = self.vars['noise_v']
if np.isscalar(ridge):
ridge_test = np.ones(test_size) * sess.run(noise_var)
# Nodes for distance operation
dist_op = self.ops['dist_op']
v1 = self.vars['v1_h']
v2 = self.vars['v2_h']
# Nodes for kernel computation
K_op = self.ops['K_op']
X_dists = self.vars['X_dists_h']
# Nodes to compute yhats/sigmas
yhat_ = self.ops['yhat_op']
K_inv_ph = self.vars['K_inv_h']
K2 = self.vars['K2_h']
K3 = self.vars['K3_h']
xy_ph = self.vars['xy_h']
ridge_test_ph = self.ops['ridge_test_h']
while arr_offset < test_size:
if arr_offset + self.batch_size_ > test_size:
end_offset = test_size
else:
end_offset = arr_offset + self.batch_size_
X_test_batch = X_test[arr_offset:end_offset]
batch_len = end_offset - arr_offset
dists1 = np.zeros([sample_size, batch_len])
for i in range(sample_size):
dists1[i] = sess.run(dist_op, feed_dict={v1: self.X_train[i],
v2: X_test_batch})
sig_val = self.ops['sig_op']
K2_ = sess.run(K_op, feed_dict={X_dists: dists1})
yhat = sess.run(yhat_, feed_dict={K2: K2_, xy_ph: self.xy_})
dists2 = np.zeros([batch_len, batch_len])
for i in range(batch_len):
dists2[i] = sess.run(dist_op, feed_dict={v1: X_test_batch[i], v2: X_test_batch})
K3_ = sess.run(K_op, feed_dict={X_dists: dists2})
sigma = np.zeros([1, batch_len], np.float32)
sigma[0] = sess.run(sig_val, feed_dict={K_inv_ph: self.K_inv, K2: K2_,
K3: K3_, ridge_test_ph: ridge_test})
sigma = np.transpose(sigma)
yhats[arr_offset: end_offset] = yhat
sigmas[arr_offset: end_offset] = sigma
arr_offset = end_offset
GPR.check_output(yhats)
GPR.check_output(sigmas)
return GPRResult(yhats, sigmas)
def get_params(self, deep=True):
return {"length_scale": self.length_scale,
"magnitude": self.magnitude,
"X_train": self.X_train,
"y_train": self.y_train,
"xy_": self.xy_,
"K": self.K,
"K_inv": self.K_inv}
def set_params(self, **parameters):
for param, val in list(parameters.items()):
setattr(self, param, val)
return self
def _reset(self):
self.X_train = None
self.y_train = None
self.xy_ = None
self.K = None
self.K_inv = None
self.graph = None
self.build_graph()
gc.collect()
class GPRGD(GPR):
GP_BETA_UCB = "UCB"
GP_BETA_CONST = "CONST"
def __init__(self,
length_scale=2.0,
magnitude=1.0,
ridge=1.0,
max_train_size=7000,
batch_size=3000,
num_threads=4,
learning_rate=0.01,
epsilon=1e-6,
max_iter=100,
sigma_multiplier=3.0,
mu_multiplier=1.0,
check_numerics=True,
debug=False,
hyperparameter_trainable=False):
super(GPRGD, self).__init__(length_scale=length_scale,
magnitude=magnitude,
ridge=ridge,
max_train_size=max_train_size,
batch_size=batch_size,
num_threads=num_threads,
check_numerics=check_numerics,
debug=debug,
hyperparameter_trainable=hyperparameter_trainable)
self.learning_rate = learning_rate
self.epsilon = epsilon
self.max_iter = max_iter
self.sigma_multiplier = sigma_multiplier
self.mu_multiplier = mu_multiplier
self.X_min = None
self.X_max = None
def fit(self, X_train, y_train, X_min, X_max): # pylint: disable=arguments-differ
super(GPRGD, self).fit(X_train, y_train)
self.X_min = X_min
self.X_max = X_max
with tf.Session(graph=self.graph,
config=tf.ConfigProto(
intra_op_parallelism_threads=self.num_threads_)) as sess:
xt_ = tf.Variable(self.X_train[0], tf.float32)
xt_ph = tf.placeholder(tf.float32)
xt_assign_op = xt_.assign(xt_ph)
init = tf.global_variables_initializer()
sess.run(init)
mag_var = self.vars['mag_v']
ls_var = self.vars['ls_v']
noise_var = self.vars['noise_v']
K2_mat = tf.transpose(tf.expand_dims(tf.sqrt(tf.reduce_sum(tf.pow(
tf.subtract(xt_, self.X_train), 2), 1)), 0))
if self.check_numerics is True:
K2_mat = tf.check_numerics(K2_mat, "K2_mat: ")
K2__ = tf.cast(mag_var * tf.exp(-K2_mat / ls_var), tf.float32) # pylint: disable=invalid-name
if self.check_numerics is True:
K2__ = tf.check_numerics(K2__, "K2__: ")
yhat_gd = tf.cast(tf.matmul(tf.transpose(K2__), self.xy_), tf.float32)
if self.check_numerics is True:
yhat_gd = tf.check_numerics(yhat_gd, message="yhat: ")
sig_val = tf.cast((tf.sqrt(mag_var + noise_var - tf.matmul(
tf.transpose(K2__), tf.matmul(self.K_inv, K2__)))), tf.float32)
if self.check_numerics is True:
sig_val = tf.check_numerics(sig_val, message="sigma: ")
LOG.debug("\nyhat_gd : %s", str(sess.run(yhat_gd)))
LOG.debug("\nsig_val : %s", str(sess.run(sig_val)))
loss = tf.squeeze(tf.subtract(self.mu_multiplier * yhat_gd,
self.sigma_multiplier * sig_val))
if self.check_numerics is True:
loss = tf.check_numerics(loss, "loss: ")
optimizer = tf.train.AdamOptimizer(learning_rate=self.learning_rate,
epsilon=self.epsilon)
# optimizer = tf.train.GradientDescentOptimizer(learning_rate=self.learning_rate)
train = optimizer.minimize(loss)
self.vars['xt_'] = xt_
self.vars['xt_ph'] = xt_ph
self.ops['xt_assign_op'] = xt_assign_op
self.ops['yhat_gd'] = yhat_gd
self.ops['sig_val2'] = sig_val
self.ops['loss_op'] = loss
self.ops['train_op'] = train
return self
def predict(self, X_test, constraint_helper=None, # pylint: disable=arguments-differ
categorical_feature_method='hillclimbing',
categorical_feature_steps=3):
self.check_fitted()
X_test = np.float32(GPR.check_array(X_test))
test_size = X_test.shape[0]
nfeats = self.X_train.shape[1]
arr_offset = 0
yhats = np.zeros([test_size, 1])
sigmas = np.zeros([test_size, 1])
minls = np.zeros([test_size, 1])
minl_confs = np.zeros([test_size, nfeats])
with tf.Session(graph=self.graph,
config=tf.ConfigProto(
intra_op_parallelism_threads=self.num_threads_)) as sess:
while arr_offset < test_size:
if arr_offset + self.batch_size_ > test_size:
end_offset = test_size
else:
end_offset = arr_offset + self.batch_size_
X_test_batch = X_test[arr_offset:end_offset]
batch_len = end_offset - arr_offset
xt_ = self.vars['xt_']
init = tf.global_variables_initializer()
sess.run(init)
sig_val = self.ops['sig_val2']
yhat_gd = self.ops['yhat_gd']
loss = self.ops['loss_op']
train = self.ops['train_op']
xt_ph = self.vars['xt_ph']
assign_op = self.ops['xt_assign_op']
yhat = np.empty((batch_len, 1))
sigma = np.empty((batch_len, 1))
minl = np.empty((batch_len, 1))
minl_conf = np.empty((batch_len, nfeats))
for i in range(batch_len):
if self.debug is True:
LOG.info("-------------------------------------------")
yhats_it = np.empty((self.max_iter + 1,)) * np.nan
sigmas_it = np.empty((self.max_iter + 1,)) * np.nan
losses_it = np.empty((self.max_iter + 1,)) * np.nan
confs_it = np.empty((self.max_iter + 1, nfeats)) * np.nan
sess.run(init)
sess.run(assign_op, feed_dict={xt_ph: X_test_batch[i]})
step = 0
for step in range(self.max_iter):
if self.debug is True:
LOG.info("Batch %d, iter %d:", i, step)
yhats_it[step] = sess.run(yhat_gd)[0][0]
sigmas_it[step] = sess.run(sig_val)[0][0]
losses_it[step] = sess.run(loss)
confs_it[step] = sess.run(xt_)
if self.debug is True:
LOG.info(" yhat: %s", str(yhats_it[step]))
LOG.info(" sigma: %s", str(sigmas_it[step]))
LOG.info(" loss: %s", str(losses_it[step]))
LOG.info(" conf: %s", str(confs_it[step]))
sess.run(train)
# constraint Projected Gradient Descent
xt = sess.run(xt_)
xt_valid = np.minimum(xt, self.X_max)
xt_valid = np.maximum(xt_valid, self.X_min)
sess.run(assign_op, feed_dict={xt_ph: xt_valid})
if constraint_helper is not None:
xt_valid = constraint_helper.apply_constraints(sess.run(xt_))
sess.run(assign_op, feed_dict={xt_ph: xt_valid})
if categorical_feature_method == 'hillclimbing':
if step % categorical_feature_steps == 0:
current_xt = sess.run(xt_)
current_loss = sess.run(loss)
new_xt = \
constraint_helper.randomize_categorical_features(
current_xt)
sess.run(assign_op, feed_dict={xt_ph: new_xt})
new_loss = sess.run(loss)
if current_loss < new_loss:
sess.run(assign_op, feed_dict={xt_ph: new_xt})
else:
raise Exception("Unknown categorial feature method: {}".format(
categorical_feature_method))
if step == self.max_iter - 1:
# Record results from final iteration
yhats_it[-1] = sess.run(yhat_gd)[0][0]
sigmas_it[-1] = sess.run(sig_val)[0][0]
losses_it[-1] = sess.run(loss)
confs_it[-1] = sess.run(xt_)
assert np.all(np.isfinite(yhats_it))
assert np.all(np.isfinite(sigmas_it))
assert np.all(np.isfinite(losses_it))
assert np.all(np.isfinite(confs_it))
# Store info for conf with min loss from all iters
if np.all(~np.isfinite(losses_it)):
min_loss_idx = 0
else:
min_loss_idx = np.nanargmin(losses_it)
yhat[i] = yhats_it[min_loss_idx]
sigma[i] = sigmas_it[min_loss_idx]
minl[i] = losses_it[min_loss_idx]
minl_conf[i] = confs_it[min_loss_idx]
minls[arr_offset:end_offset] = minl
minl_confs[arr_offset:end_offset] = minl_conf
yhats[arr_offset:end_offset] = yhat
sigmas[arr_offset:end_offset] = sigma
arr_offset = end_offset
GPR.check_output(yhats)
GPR.check_output(sigmas)
GPR.check_output(minls)
GPR.check_output(minl_confs)
return GPRGDResult(yhats, sigmas, minls, minl_confs)
@staticmethod
def calculate_sigma_multiplier(t, ndim, bound=0.1):
assert t > 0
assert ndim > 0
assert bound > 0 and bound <= 1
beta = 2 * np.log(ndim * (t**2) * (np.pi**2) / 6 * bound)
if beta > 0:
beta = np.sqrt(beta)
else:
beta = 1
return beta
# def gp_tf(X_train, y_train, X_test, ridge, length_scale, magnitude, batch_size=3000):
# with tf.Graph().as_default():
# y_best = tf.cast(tf.reduce_min(y_train, 0, True), tf.float32)
# sample_size = X_train.shape[0]
# train_size = X_test.shape[0]
# arr_offset = 0
# yhats = np.zeros([train_size, 1])
# sigmas = np.zeros([train_size, 1])
# eips = np.zeros([train_size, 1])
# X_train = np.float32(X_train)
# y_train = np.float32(y_train)
# X_test = np.float32(X_test)
# ridge = np.float32(ridge)
#
# v1 = tf.placeholder(tf.float32,name="v1")
# v2 = tf.placeholder(tf.float32,name="v2")
# dist_op = tf.sqrt(tf.reduce_sum(tf.pow(tf.subtract(v1, v2), 2), 1))
# try:
# sess = tf.Session(config=tf.ConfigProto(log_device_placement=False))
#
# dists = np.zeros([sample_size,sample_size])
# for i in range(sample_size):
# dists[i] = sess.run(dist_op,feed_dict={v1:X_train[i], v2:X_train})
#
#
# dists = tf.cast(dists, tf.float32)
# K = magnitude * tf.exp(-dists/length_scale) + tf.diag(ridge);
#
# K2 = tf.placeholder(tf.float32, name="K2")
# K3 = tf.placeholder(tf.float32, name="K3")
#
# x = tf.matmul(tf.matrix_inverse(K), y_train)
# yhat_ = tf.cast(tf.matmul(tf.transpose(K2), x), tf.float32);
# sig_val = tf.cast((tf.sqrt(tf.diag_part(K3 - tf.matmul(tf.transpose(K2),
# tf.matmul(tf.matrix_inverse(K),
# K2))))),
# tf.float32)
#
# u = tf.placeholder(tf.float32, name="u")
# phi1 = 0.5 * tf.erf(u / np.sqrt(2.0)) + 0.5
# phi2 = (1.0 / np.sqrt(2.0 * np.pi)) * tf.exp(tf.square(u) * (-0.5));
# eip = (tf.multiply(u, phi1) + phi2);
#
# while arr_offset < train_size:
# if arr_offset + batch_size > train_size:
# end_offset = train_size
# else:
# end_offset = arr_offset + batch_size;
#
# xt_ = X_test[arr_offset:end_offset];
# batch_len = end_offset - arr_offset
#
# dists = np.zeros([sample_size, batch_len])
# for i in range(sample_size):
# dists[i] = sess.run(dist_op, feed_dict={v1:X_train[i], v2:xt_})
#
# K2_ = magnitude * tf.exp(-dists / length_scale);
# K2_ = sess.run(K2_)
#
# dists = np.zeros([batch_len, batch_len])
# for i in range(batch_len):
# dists[i] = sess.run(dist_op, feed_dict={v1:xt_[i], v2:xt_})
# K3_ = magnitude * tf.exp(-dists / length_scale);
# K3_ = sess.run(K3_)
#
# yhat = sess.run(yhat_, feed_dict={K2:K2_})
#
# sigma = np.zeros([1, batch_len], np.float32)
# sigma[0] = (sess.run(sig_val, feed_dict={K2:K2_, K3:K3_}))
# sigma = np.transpose(sigma)
#
# u_ = tf.cast(tf.div(tf.subtract(y_best, yhat), sigma), tf.float32)
# u_ = sess.run(u_)
# eip_p = sess.run(eip, feed_dict={u:u_})
# eip_ = tf.multiply(sigma, eip_p)
# yhats[arr_offset:end_offset] = yhat
# sigmas[arr_offset:end_offset] = sigma;
# eips[arr_offset:end_offset] = sess.run(eip_);
# arr_offset = end_offset
#
# finally:
# sess.close()
#
# return yhats, sigmas, eips
def euclidean_mat(X, y, sess):
x_n = X.shape[0]
y_n = y.shape[0]
z = np.zeros([x_n, y_n])
for i in range(x_n):
v1 = X[i]
tmp = []
for j in range(y_n):
v2 = y[j]
tmp.append(tf.sqrt(tf.reduce_sum(tf.pow(tf.subtract(v1, v2), 2))))
z[i] = (sess.run(tmp))
return z
def gd_tf(xs, ys, xt, ridge, length_scale=1.0, magnitude=1.0, max_iter=50):
LOG.debug("xs shape: %s", str(xs.shape))
LOG.debug("ys shape: %s", str(ys.shape))
LOG.debug("xt shape: %s", str(xt.shape))
with tf.Graph().as_default():
# y_best = tf.cast(tf.reduce_min(ys,0,True),tf.float32); #array
# yhat_gd = tf.check_numerics(yhat_gd, message="yhat: ")
sample_size = xs.shape[0]
nfeats = xs.shape[1]
test_size = xt.shape[0]
# arr_offset = 0
ini_size = xt.shape[0]
yhats = np.zeros([test_size, 1])
sigmas = np.zeros([test_size, 1])
minl = np.zeros([test_size, 1])
new_conf = np.zeros([test_size, nfeats])
xs = np.float32(xs)
ys = np.float32(ys)
xt_ = tf.Variable(xt[0], tf.float32)
sess = tf.Session(config=tf.ConfigProto(intra_op_parallelism_threads=8))
init = tf.global_variables_initializer()
sess.run(init)
ridge = np.float32(ridge)
v1 = tf.placeholder(tf.float32, name="v1")
v2 = tf.placeholder(tf.float32, name="v2")
dist = tf.sqrt(tf.reduce_sum(tf.pow(tf.subtract(v1, v2), 2), 1))
tmp = np.zeros([sample_size, sample_size])
for i in range(sample_size):
tmp[i] = sess.run(dist, feed_dict={v1: xs[i], v2: xs})
tmp = tf.cast(tmp, tf.float32)
K = magnitude * tf.exp(-tmp / length_scale) + tf.diag(ridge)
LOG.debug("K shape: %s", str(sess.run(K).shape))
K2_mat = tf.sqrt(tf.reduce_sum(tf.pow(tf.subtract(xt_, xs), 2), 1))
K2_mat = tf.transpose(tf.expand_dims(K2_mat, 0))
K2 = tf.cast(tf.exp(-K2_mat / length_scale), tf.float32)
x = tf.matmul(tf.matrix_inverse(K), ys)
x = sess.run(x)
yhat_ = tf.cast(tf.matmul(tf.transpose(K2), x), tf.float32)
sig_val = tf.cast((tf.sqrt(magnitude - tf.matmul(
tf.transpose(K2), tf.matmul(tf.matrix_inverse(K), K2)))), tf.float32)
LOG.debug('yhat shape: %s', str(sess.run(yhat_).shape))
LOG.debug('sig_val shape: %s', str(sess.run(sig_val).shape))
yhat_ = tf.check_numerics(yhat_, message='yhat: ')
sig_val = tf.check_numerics(sig_val, message='sig_val: ')
loss = tf.squeeze(tf.subtract(yhat_, sig_val))
loss = tf.check_numerics(loss, message='loss: ')
# optimizer = tf.train.GradientDescentOptimizer(0.1)
LOG.debug('loss: %s', str(sess.run(loss)))
optimizer = tf.train.AdamOptimizer(0.1)
train = optimizer.minimize(loss)
init = tf.global_variables_initializer()
sess.run(init)
for i in range(ini_size):
assign_op = xt_.assign(xt[i])
sess.run(assign_op)
for step in range(max_iter):
LOG.debug('sample #: %d, iter #: %d, loss: %s', i, step, str(sess.run(loss)))
sess.run(train)
yhats[i] = sess.run(yhat_)[0][0]
sigmas[i] = sess.run(sig_val)[0][0]
minl[i] = sess.run(loss)
new_conf[i] = sess.run(xt_)
return yhats, sigmas, minl, new_conf
def main():
pass
def create_random_matrices(n_samples=3000, n_feats=12, n_test=4444):
X_train = np.random.rand(n_samples, n_feats)
y_train = np.random.rand(n_samples, 1)
X_test = np.random.rand(n_test, n_feats)
length_scale = np.random.rand()
magnitude = np.random.rand()
ridge = np.ones(n_samples) * np.random.rand()
return X_train, y_train, X_test, length_scale, magnitude, ridge
if __name__ == "__main__":
main()