add PPO

codes/PPO/model.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+# coding=utf-8
+'''
+Author: John
+Email: johnjim0816@gmail.com
+Date: 2021-03-23 15:29:24
+LastEditor: John
+LastEditTime: 2021-03-23 15:29:52
+Discription: 
+Environment: 
+'''
+import torch.nn as nn
+from torch.distributions.categorical import Categorical
+class Actor(nn.Module):
+    def __init__(self,state_dim, action_dim,
+            hidden_dim=256):
+        super(Actor, self).__init__()
+
+        self.actor = nn.Sequential(
+                nn.Linear(state_dim, hidden_dim),
+                nn.ReLU(),
+                nn.Linear(hidden_dim, hidden_dim),
+                nn.ReLU(),
+                nn.Linear(hidden_dim, action_dim),
+                nn.Softmax(dim=-1)
+        )
+    def forward(self, state):
+        dist = self.actor(state)
+        dist = Categorical(dist)
+        return dist
+
+class Critic(nn.Module):
+    def __init__(self, state_dim,hidden_dim=256):
+        super(Critic, self).__init__()
+        self.critic = nn.Sequential(
+                nn.Linear(state_dim, hidden_dim),
+                nn.ReLU(),
+                nn.Linear(hidden_dim, hidden_dim),
+                nn.ReLU(),
+                nn.Linear(hidden_dim, 1)
+        )
+    def forward(self, state):
+        value = self.critic(state)
+        return value