[NNVM][DARKNET]Logistic activation added (#1477)

nnvm/python/nnvm/frontend/darknet.py

@@ -301,7 +301,9 @@ def _darknet_region(inputs, attrs):
 def _darknet_activations(inputs, attrs):
     """Process the activation function."""
     act = _darknet_required_attr(attrs, 'activation')
-    if ACTIVATION.RELU == act:
+    if ACTIVATION.LOGISTIC == act:
+        act_type = 'sigmoid'
+    elif ACTIVATION.RELU == act:
         act_type = 'relu'
     elif ACTIVATION.TANH == act:
         act_type = 'tanh'
@@ -323,6 +325,9 @@ def _darknet_activations(inputs, attrs):
         sym = _darknet_get_nnvm_op(op_name)(*inputs, **new_attrs)
     elif act_type in ['elu']:
         sym = -1 * _sym.relu(1 - _sym.exp(*inputs)) + _sym.relu(*inputs)
+    elif act_type in ['sigmoid']:
+        op_name, new_attrs = act_type, {}
+        sym = _darknet_get_nnvm_op(op_name)(*inputs, **new_attrs)
     else:
         _darknet_raise_not_supported('act_type: ' + act_type)
     return sym, None

nnvm/tests/python/frontend/darknet/test_forward.py

@@ -324,6 +324,32 @@ def test_forward_rnn():
     test_rnn_forward(net)
     LIB.free_network(net)
 
+def test_forward_activation_logistic():
+    '''test logistic activation layer'''
+    net = LIB.make_network(1)
+    batch = 1
+    h = 224
+    w = 224
+    c = 3
+    n = 32
+    groups = 1
+    size = 3
+    stride = 2
+    padding = 0
+    activation = 0
+    batch_normalize = 0
+    binary = 0
+    xnor = 0
+    adam = 0
+    layer_1 = LIB.make_convolutional_layer(batch, h, w, c, n, groups, size, stride, padding,
+                                           activation, batch_normalize, binary, xnor, adam)
+    net.layers[0] = layer_1
+    net.w = w
+    net.h = h
+    LIB.resize_network(net, net.w, net.h)
+    test_forward(net)
+    LIB.free_network(net)
+
 if __name__ == '__main__':
     test_forward_resnet50()
     test_forward_alexnet()
@@ -342,3 +368,5 @@ if __name__ == '__main__':
     test_forward_reorg()
     test_forward_region()
     test_forward_elu()
+    test_forward_rnn()
+    test_forward_activation_logistic()
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