change to 3x3 conv filters, for ease of reading dimension in net (#515)

Author: WillRNaylor

beginner_source/blitz/neural_networks_tutorial.py

@@ -46,12 +46,12 @@ class Net(nn.Module):
 
     def __init__(self):
         super(Net, self).__init__()
-        # 1 input image channel, 6 output channels, 5x5 square convolution
+        # 1 input image channel, 6 output channels, 3x3 square convolution
         # kernel
-        self.conv1 = nn.Conv2d(1, 6, 5)
-        self.conv2 = nn.Conv2d(6, 16, 5)
+        self.conv1 = nn.Conv2d(1, 6, 3)
+        self.conv2 = nn.Conv2d(6, 16, 3)
         # an affine operation: y = Wx + b
-        self.fc1 = nn.Linear(16 * 5 * 5, 120)
+        self.fc1 = nn.Linear(16 * 6 * 6, 120)  # 6*6 from image dimension 
         self.fc2 = nn.Linear(120, 84)
         self.fc3 = nn.Linear(84, 10)