From 31db0f78f7dc91736f493a829bfe8289ed61e44d Mon Sep 17 00:00:00 2001
From: Bolo <36342729+PppBr@users.noreply.github.com>
Date: Sat, 2 Mar 2019 22:15:38 -0600
Subject: [PATCH] implement tf.distribution and keep developing on NaiveBayes
 Classifier

---
 .../Distributions/distribution.py.cs          | 89 +++++++++++++++++++
 .../Operations/Distributions/normal.py.cs     | 11 +++
 .../NaiveBayesClassifier.cs                   | 16 ++++
 3 files changed, 116 insertions(+)
 create mode 100644 src/TensorFlowNET.Core/Operations/Distributions/distribution.py.cs
 create mode 100644 src/TensorFlowNET.Core/Operations/Distributions/normal.py.cs

diff --git a/src/TensorFlowNET.Core/Operations/Distributions/distribution.py.cs b/src/TensorFlowNET.Core/Operations/Distributions/distribution.py.cs
new file mode 100644
index 00000000..984dc2a9
--- /dev/null
+++ b/src/TensorFlowNET.Core/Operations/Distributions/distribution.py.cs
@@ -0,0 +1,89 @@
+//Base classes for probability distributions.
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+
+namespace Tensorflow
+{
+    abstract class _BaseDistribution : Object
+    {
+        // Abstract base class needed for resolving subclass hierarchy.
+    }
+
+    /// <summary>
+    /// A generic probability distribution base class.
+    /// Distribution is a base class for constructing and organizing properties
+    /// (e.g., mean, variance) of random variables (e.g, Bernoulli, Gaussian). 
+    /// </summary>
+    class Distribution : _BaseDistribution
+    {
+        public TF_DataType _dtype {get;set;}
+        public ReparameterizationType _reparameterization_type {get;set;}
+        public bool _validate_args {get;set;}
+        public bool _allow_nan_stats {get;set;}
+        public Dictionary<object, object> _parameters  {get;set;}
+        public List<object> _graph_parents  {get;set;}
+        public string _name  {get;set;}
+
+        /// <summary>
+        /// Constructs the `Distribution'     
+        /// **This is a private method for subclass use.**
+        /// </summary>
+        /// <param name="dtype"> The type of the event samples. `None` implies no type-enforcement.</param>
+        /// <param name="reparameterization_type"> Instance of `ReparameterizationType`.
+        /// If `distributions.FULLY_REPARAMETERIZED`, this `Distribution` can be reparameterized
+        /// in terms of some standard distribution with a function whose Jacobian is constant for the support 
+        /// of the standard distribution. If `distributions.NOT_REPARAMETERIZED`,
+        /// then no such reparameterization is available.</param>
+        /// <param name="validate_args"> When `True` distribution parameters are checked for validity despite
+        /// possibly degrading runtime performance. When `False` invalid inputs silently render incorrect outputs.</param>
+        /// <param name="allow_nan_stats"> When `True`, statistics (e.g., mean, mode, variance) use the value "`NaN`" 
+        /// to indicate the result is undefined. When `False`, an exception is raised if one or more of the statistic's
+        /// batch members are undefined.</param>
+        /// <param name = "parameters"> `dict` of parameters used to instantiate this `Distribution`.</param>
+        /// <param name = "graph_parents"> `list` of graph prerequisites of this `Distribution`.</param>
+        /// <param name = "name"> Name prefixed to Ops created by this class. Default: subclass name.</param>
+        /// <returns> Two `Tensor` objects: `mean` and `variance`.</returns>
+
+        /* 
+        private Distribution (
+                TF_DataType dtype,
+                ReparameterizationType reparameterization_type,
+                bool validate_args,
+                bool allow_nan_stats,
+                Dictionary<object, object> parameters=null,
+                List<object> graph_parents=null,
+                string name= null)
+                {
+                    this._dtype = dtype;
+                    this._reparameterization_type = reparameterization_type;
+                    this._allow_nan_stats = allow_nan_stats;
+                    this._validate_args = validate_args;
+                    this._parameters = parameters;
+                    this._graph_parents = graph_parents;
+                    this._name = name;
+                }
+        */
+    }
+
+    /// <summary>
+    /// Instances of this class represent how sampling is reparameterized.
+    /// Two static instances exist in the distributions library, signifying
+    /// one of two possible properties for samples from a distribution:
+    /// `FULLY_REPARAMETERIZED`: Samples from the distribution are fully
+    /// reparameterized, and straight-through gradients are supported.
+    /// `NOT_REPARAMETERIZED`: Samples from the distribution are not fully
+    /// reparameterized, and straight-through gradients are either partially
+    /// unsupported or are not supported at all. In this case, for purposes of
+    /// e.g. RL or variational inference, it is generally safest to wrap the
+    /// sample results in a `stop_gradients` call and use policy
+    /// gradients / surrogate loss instead.
+    /// </summary>
+    class ReparameterizationType
+    {
+
+    }
+
+
+}
\ No newline at end of file
diff --git a/src/TensorFlowNET.Core/Operations/Distributions/normal.py.cs b/src/TensorFlowNET.Core/Operations/Distributions/normal.py.cs
new file mode 100644
index 00000000..67bc2ea8
--- /dev/null
+++ b/src/TensorFlowNET.Core/Operations/Distributions/normal.py.cs
@@ -0,0 +1,11 @@
+namespace Tensorflow
+{
+    class Normal : Distribution
+    {
+        public Normal (Tensor loc, Tensor scale, bool validate_args=false, bool allow_nan_stats=true, string name="Normal")
+        {
+            
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/test/TensorFlowNET.Examples/NaiveBayesClassifier.cs b/test/TensorFlowNET.Examples/NaiveBayesClassifier.cs
index 6d6c02ab..3a559d16 100644
--- a/test/TensorFlowNET.Examples/NaiveBayesClassifier.cs
+++ b/test/TensorFlowNET.Examples/NaiveBayesClassifier.cs
@@ -54,6 +54,22 @@ namespace TensorFlowNET.Examples
             // estimate mean and variance for each class / feature
             // shape : nb_classes * nb_features
             var cons = tf.constant(points_by_class);
+            Tuple<Tensor, Tensor> tup = tf.nn.moments(cons, new int[]{1});
+            var mean = tup.Item1;
+            var variance = tup.Item2;
+            // Create a 3x2 univariate normal distribution with the 
+            // Known mean and variance           
+            // var dist = tf.distributions.Normal(loc=mean, scale=tf.sqrt(variance));
+
+        }
+
+        public void predict (NDArray X)
+        {
+            // assert self.dist is not None
+            // nb_classes, nb_features = map(int, self.dist.scale.shape)
+
+
+            throw new NotFiniteNumberException();
         }
     }
 }