Ejemplo n.º 1
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 def onepred(i):
     f = compute_f(alpha[i], rho[i], beta[i], eta[i])
     gprm = tfd.GaussianProcessRegressionModel(
         kernel=SqExpKernel(alpha[i], rho[i]),
         index_points=index_points.astype(dtype),
         observation_index_points=X,
         jitter=1e-6,
         observations=f)
     return gprm.sample().numpy()
Ejemplo n.º 2
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 def get_model_infer(self, X_test):
     return tfd.GaussianProcessRegressionModel(
         kernel=self.model_train.
         kernel,  # Reuse the same kernel instance, with the same params
         index_points=X_test,
         observation_index_points=self.model_train.index_points,
         observations=self.y_train,
         observation_noise_variance=self.model_train.
         observation_noise_variance,
         predictive_noise_variance=tf.constant(0., dtype=np.float64))
Ejemplo n.º 3
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 def body(i, ys):
     y = tf.gather(observed_dz_dxt, i, axis=1)
     posterior2 = tfd.GaussianProcessRegressionModel(
         kernel=kernel2,
         mean_fn=lambda x: tf.reduce_mean(y, keep_dims=True),
         index_points=new_Xt,
         observation_index_points=observed_Xt,
         observations=y,
         observation_noise_variance=0.,
         predictive_noise_variance=0.)
     ys = tf.concat([ys, posterior2.mean()], axis=0)
     return i + 1, ys
Ejemplo n.º 4
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def tf_gp_regression_model(kernel, pred_idx_pts, obs_idx_pts, obs, obs_noise_var, pred_noise_var):
    pred_idx_pts_Var = tf.cast(pred_idx_pts, dtype=tf.float64, name="pred_idx_pts_Var")
    obs_idx_pts_Var = tf.cast(obs_idx_pts, dtype=tf.float64, name="obs_idx_pts_Var")
    obs_Var = tf.cast(obs, dtype=tf.float64, name="obs_Var")
    obs_Var = tf.reshape(obs_Var, shape=[-1], name="obs_Var")

    obs_noise_Var = tf.Variable(obs_noise_var, dtype=tf.float64, name="obs_noise_var")
    gprm = tfd.GaussianProcessRegressionModel(
        kernel=kernel,
        index_points=pred_idx_pts_Var,
        observation_index_points=obs_idx_pts_Var,
        observations=obs_Var,
        observation_noise_variance=obs_noise_Var,
        predictive_noise_variance=pred_noise_var)
    return gprm
Ejemplo n.º 5
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# Having trained the model, we'd like to sample from the posterior conditioned
# on observations. We'd like the samples to be at points other than the training inputs.
predictive_index_points_ = np.linspace(-1.2, 1.2, 200, dtype=np.float64)
# Reshape to [200, 1] -- 1 is the dimensionality of the feature space.
predictive_index_points_ = predictive_index_points_[..., np.newaxis]

print("predictive_index_points_.shape", predictive_index_points_.shape)
print("observation_index_points_.shape", observation_index_points_.shape)
print("observations_.shape", observations_.shape)



gprm = tfd.GaussianProcessRegressionModel(
    kernel=kernel,  # Reuse the same kernel instance, with the same params
    index_points=predictive_index_points_,
    observation_index_points=observation_index_points_,
    observations=observations_,
    observation_noise_variance=observation_noise_variance,
    predictive_noise_variance=0.)

#####################################
# Create op to draw  50 independent samples, each of which is a *joint* draw
# from the posterior at the predictive_index_points_. Since we have 200 input
# locations as defined above, this posterior distribution over corresponding
# function values is a 200-dimensional multivariate Gaussian distribution!
num_samples = 50
samples = gprm.sample(num_samples)

# Draw samples and visualize.
samples_ = sess.run(samples)
Ejemplo n.º 6
0
        FIRSTELEM_=False
    else:
        observations = np.vstack((observations, z))
observations = np.reshape(observations, [-1])

observation_noise_variance=0.01

# print(kernel)
print(pred_pts)
# print(xy_pts)
# print(observations)

gprm = tfd.GaussianProcessRegressionModel(
    kernel=kernel,  # Reuse the same kernel instance, with the same params
    index_points=pred_pts,  # 1D_emb:(400,1), 2D_emb:(200,2)
    observation_index_points=xy_pts,  # (15,1) (15,2)
    observations=observations,  # (15,)
    observation_noise_variance=observation_noise_variance,
    validate_args=True)

samples = gprm.sample(NUM_GP_SAMPLES)
gpsamples = sess.run(samples)

#TODO
# fix gprm index_.....
# condition somehow

def plot2D_samples(X, Y): # Plot the true function, observations, and posterior samples.

    plt.figure(figsize=(X, Y))
    # plt.plot(pred_pts, sinusoid(predictive_index_points_),
Ejemplo n.º 7
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with tf.name_scope('PCA'):
    pca = PCA(config.n_components)
    observed_Xt = pca.fit_transform(observed_X)
    observed_dz_dxt = pca.transform_gradient(observed_dz_dx)
    new_Xt = pca.transform(new_X)

with tf.name_scope('prediction'):
    with tf.name_scope('function_process'):
        with tf.name_scope('kernel'):
            kernel1 = tfk.ExponentiatedQuadratic(amplitude, length_scale)
        with tf.name_scope('posterior'):
            posterior1 = tfd.GaussianProcessRegressionModel(
                kernel=kernel1,
                mean_fn=lambda x: tf.reduce_mean(observed_y, keep_dims=True),
                index_points=new_Xt,
                observation_index_points=observed_Xt,
                observations=observed_y,
                observation_noise_variance=0.,
                predictive_noise_variance=0.)
            pred_y = posterior1.mean()
            y_variance = posterior1.variance()

    with tf.name_scope('derivative_process'):
        _init_index = tf.constant(0)
        _pred_dzt = tf.constant([], dtype=tf.float64)
        with tf.name_scope('kernel'):
            kernel2 = ApproximateExponentialQuadraticHessian(
                amplitude, length_scale)
        with tf.name_scope('posterior'):

            def cond(i, ys):