Develop/v0.3.3

pixyz/__init__.py

@@ -1,2 +1,2 @@
 name = "pixyz"
-__version__ = "0.3.2"
+__version__ = "0.3.3"

pixyz/distributions/__init__.py

@@ -28,6 +28,7 @@
 )
 
 from .poe import ProductOfNormal, ElementWiseProductOfNormal
+from .moe import MixtureOfNormal
 
 from .mixture_distributions import MixtureModel
 
@@ -55,6 +56,7 @@
     'MarginalizeVarDistribution',
     'ProductOfNormal',
     'ElementWiseProductOfNormal',
+    'MixtureOfNormal',
     'MixtureModel',
 
     'TransformedDistribution',

pixyz/distributions/distributions.py

@@ -69,14 +69,20 @@ def _reversed_name_dict(self):
     def __apply_dict(dict, var):
         return [dict[var_name] if var_name in dict else var_name for var_name in var]
 
-    def sample(self, values, sample_option):
-        global_input_var = self.__apply_dict(self._reversed_name_dict, self.dist.input_var)
+    def _get_local_input_dict(self, values, input_var=None):
+        if not input_var:
+            input_var = self.dist.input_var
+        global_input_var = self.__apply_dict(self._reversed_name_dict, input_var)
 
         if any(var_name not in values for var_name in global_input_var):
-            raise ValueError("lack of some condition variables")
+            raise ValueError("lack of some variables")
         input_dict = get_dict_values(values, global_input_var, return_dict=True)
 
         local_input_dict = replace_dict_keys(input_dict, self.name_dict)
+        return local_input_dict
+
+    def sample(self, values, sample_option):
+        local_input_dict = self._get_local_input_dict(values)
 
         # Overwrite log_prob_option with self.option to give priority to local settings such as batch_n
         option = dict(sample_option)
@@ -94,19 +100,34 @@ def sample(self, values, sample_option):
         return sample
 
     def get_log_prob(self, values, log_prob_option):
-        global_input_var = self.__apply_dict(self._reversed_name_dict, list(self.dist.var) + list(self.dist.cond_var))
-
-        if any(var_name not in values for var_name in global_input_var):
-            raise ValueError("lack of some variables")
-        input_dict = get_dict_values(values, global_input_var, return_dict=True)
-        local_input_dict = replace_dict_keys(input_dict, self.name_dict)
+        local_input_dict = self._get_local_input_dict(values, list(self.dist.var) + list(self.dist.cond_var))
 
         # Overwrite log_prob_option with self.option to give priority to local settings such as batch_n
         option = dict(log_prob_option)
         option.update(self.option)
         log_prob = self.dist.get_log_prob(local_input_dict, **option)
         return log_prob
 
+    def get_params(self, params_dict={}, **kwargs):
+        orig_params_dict = self._get_local_input_dict(params_dict)
+        params = self.dist.get_params(orig_params_dict, **kwargs)
+        return params
+
+    def sample_mean(self, values={}):
+        local_input_dict = self._get_local_input_dict(values)
+        result = self.dist.sample_mean(local_input_dict)
+        return result
+
+    def sample_variance(self, values={}):
+        local_input_dict = self._get_local_input_dict(values)
+        result = self.dist.sample_variance(local_input_dict)
+        return result
+
+    def get_entropy(self, values={}, sum_features=True, feature_dims=None):
+        local_input_dict = self._get_local_input_dict(values)
+        result = self.dist.get_entropy(local_input_dict, sum_features, feature_dims)
+        return result
+
     @property
     def input_var(self):
         return self.__apply_dict(self._reversed_name_dict, self.dist.input_var)
@@ -673,6 +694,34 @@ def _get_log_prob(self, x_dict, sum_features=True, feature_dims=None, **kwargs):
             return 0
         return log_prob
 
+    def get_params(self, params_dict={}, **kwargs):
+        if len(self.var) != 1:
+            raise NotImplementedError()
+        for factor in self.factors():
+            result = factor.get_params(params_dict, **kwargs)
+        return result
+
+    def sample_mean(self, x_dict={}):
+        if len(self.var) != 1:
+            raise NotImplementedError()
+        for factor in self.factors():
+            result = factor.sample_variance(x_dict)
+        return result
+
+    def sample_variance(self, x_dict={}):
+        if len(self.var) != 1:
+            raise NotImplementedError()
+        for factor in self.factors():
+            result = factor.sample_variance(x_dict)
+        return result
+
+    def get_entropy(self, x_dict={}, sum_features=True, feature_dims=None):
+        if len(self.var) != 1:
+            raise NotImplementedError()
+        for factor in self.factors():
+            result = factor.get_entropy(x_dict, sum_features, feature_dims)
+        return result
+
     @property
     def has_reparam(self):
         return all(factor.dist.has_reparam for factor in self.factors())
@@ -1043,6 +1092,8 @@ def sample_mean(self, x_dict={}):
                   1.2810, -0.6681]])
 
         """
+        if self.graph:
+            return self.graph.sample_mean(x_dict)
         raise NotImplementedError()
 
     def sample_variance(self, x_dict={}):
@@ -1073,6 +1124,8 @@ def sample_variance(self, x_dict={}):
         tensor([[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.]])
 
         """
+        if self.graph:
+            return self.graph.sample_variance(x_dict)
         raise NotImplementedError()
 
     def get_log_prob(self, x_dict, sum_features=True, feature_dims=None, **kwargs):
@@ -1154,6 +1207,13 @@ def get_entropy(self, x_dict={}, sum_features=True, feature_dims=None):
         tensor([14.1894])
 
         """
+        if self.graph:
+            return self.graph.get_entropy(x_dict, sum_features, feature_dims)
+        raise NotImplementedError()
+
+    def get_params(self, params_dict={}, **kwargs):
+        if self.graph:
+            return self.graph.get_params(params_dict, **kwargs)
         raise NotImplementedError()
 
     def log_prob(self, sum_features=True, feature_dims=None):
@@ -1700,15 +1760,6 @@ def __repr__(self):
     def forward(self, *args, **kwargs):
         return self.p(*args, **kwargs)
 
-    def sample_mean(self, x_dict={}):
-        return self.p.sample_mean(x_dict)
-
-    def sample_variance(self, x_dict={}):
-        return self.p.sample_variance(x_dict)
-
-    def get_entropy(self, x_dict={}, sum_features=True, feature_dims=None):
-        return self.p.get_entropy(x_dict, sum_features, feature_dims)
-
     @property
     def distribution_name(self):
         return self.p.distribution_name

pixyz/distributions/moe.py

@@ -0,0 +1,169 @@
+from __future__ import print_function
+import torch
+from torch import nn
+import numpy as np
+
+from ..utils import tolist, get_dict_values
+from ..distributions import Normal
+
+
+class MixtureOfNormal(Normal):
+    r"""Mixture of normal distributions.
+    .. math::
+        p(z|x,y) = p(z|x) + p(z|y)
+    In this models, :math:`p(z|x)` and :math:`p(a|y)` perform as `experts`.
+
+    References
+    ----------
+    [Shi+ 2019] Variational Mixture-of-Experts Autoencoders for Multi-Modal Deep Generative Models
+
+    """
+
+    def __init__(self, p=[], weight_modalities=None, name="p", features_shape=torch.Size()):
+        """
+        Parameters
+        ----------
+        p : :obj:`list` of :class:`pixyz.distributions.Normal`.
+            List of experts.
+        name : :obj:`str`, defaults to "p"
+            Name of this distribution.
+            This name is displayed in prob_text and prob_factorized_text.
+        features_shape : :obj:`torch.Size` or :obj:`list`, defaults to torch.Size())
+            Shape of dimensions (features) of this distribution.
+        """
+
+        p = tolist(p)
+        if len(p) == 0:
+            raise ValueError()
+
+        if weight_modalities is None:
+            weight_modalities = torch.ones(len(p)) / float(len(p))
+
+        elif len(weight_modalities) != len(p):
+            raise ValueError()
+
+        var = p[0].var
+        cond_var = []
+
+        for _p in p:
+            if _p.var != var:
+                raise ValueError()
+
+            cond_var += _p.cond_var
+
+        cond_var = list(set(cond_var))
+
+        super().__init__(var=var, cond_var=cond_var, name=name, features_shape=features_shape)
+        self.p = nn.ModuleList(p)
+        self.weight_modalities = weight_modalities
+
+    def _get_expert_params(self, params_dict={}, **kwargs):
+        """Get the output parameters of all experts.
+        Parameters
+        ----------
+        params_dict : dict
+        **kwargs
+            Arbitrary keyword arguments.
+        Returns
+        -------
+        loc : torch.Tensor
+            Concatenation of mean vectors for specified experts. (n_expert, n_batch, output_dim)
+        scale : torch.Tensor
+            Concatenation of the square root of a diagonal covariance matrix for specified experts.
+            (n_expert, n_batch, output_dim)
+        weight : np.array
+            (n_expert, )
+        """
+
+        loc = []
+        scale = []
+
+        for i, _p in enumerate(self.p):
+            inputs_dict = get_dict_values(params_dict, _p.cond_var, True)
+            if len(inputs_dict) != 0:
+                outputs = _p.get_params(inputs_dict, **kwargs)
+                loc.append(outputs["loc"])
+                scale.append(outputs["scale"])
+
+        loc = torch.stack(loc)
+        scale = torch.stack(scale)
+
+        return loc, scale
+
+    def get_params(self, params_dict={}, **kwargs):
+        # experts
+        if len(params_dict) > 0:
+            loc, scale = self._get_expert_params(params_dict, **kwargs)  # (n_expert, n_batch, output_dim)
+        else:
+            raise ValueError()
+
+        output_loc, output_scale = self._compute_expert_params(loc, scale)
+        output_dict = {"loc": output_loc, "scale": output_scale}
+
+        return output_dict
+
+    def _compute_expert_params(self, loc, scale):
+        """Compute parameters for the product of experts.
+        Is is assumed that unspecified experts are excluded from inputs.
+        Parameters
+        ----------
+        loc : torch.Tensor
+            Concatenation of mean vectors for specified experts. (n_expert, n_batch, output_dim)
+        scale : torch.Tensor
+            Concatenation of the square root of a diagonal covariance matrix for specified experts.
+            (n_expert, n_batch, output_dim)
+        Returns
+        -------
+        output_loc : torch.Tensor
+            Mean vectors for this distribution. (n_batch, output_dim)
+        output_scale : torch.Tensor
+            The square root of diagonal covariance matrices for this distribution. (n_batch, output_dim)
+        """
+        num_samples = loc.shape[1]
+
+        idx_start = []
+        idx_end = []
+        for k in range(0, len(self.weight_modalities)):
+            if k == 0:
+                i_start = 0
+            else:
+                i_start = int(idx_end[k - 1])
+            if k == len(self.weight_modalities) - 1:
+                i_end = num_samples
+            else:
+                i_end = i_start + int(np.floor(num_samples * self.weight_modalities[k]))
+            idx_start.append(i_start)
+            idx_end.append(i_end)
+
+        idx_end[-1] = num_samples
+
+        output_loc = torch.cat([loc[k, idx_start[k]:idx_end[k], :] for k in range(len(self.weight_modalities))])
+        output_scale = torch.cat([scale[k, idx_start[k]:idx_end[k], :] for k in range(len(self.weight_modalities))])
+
+        return output_loc, output_scale
+
+    def _get_input_dict(self, x, var=None):
+        if var is None:
+            var = self.input_var
+
+        if type(x) is torch.Tensor:
+            checked_x = {var[0]: x}
+
+        elif type(x) is list:
+            # TODO: we need to check if all the elements contained in this list are torch.Tensor.
+            checked_x = dict(zip(var, x))
+
+        elif type(x) is dict:
+            # point of modification
+            checked_x = x
+
+        else:
+            raise ValueError("The type of input is not valid, got %s." % type(x))
+
+        return get_dict_values(checked_x, var, return_dict=True)
+
+    def get_log_prob(self, x_dict, sum_features=True, feature_dims=None):
+        log_prob = torch.stack([w * p.get_log_prob(x_dict, sum_features=sum_features, feature_dims=feature_dims) for p, w in zip(self.p, self.weight_modalities)])
+        log_prob = torch.logsumexp(log_prob, dim=0)
+
+        return log_prob