tmp commit - toward 0.0.1

pina/adaptive_functions/adaptive_sin.py

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+import torch
+from torch.nn.parameter import Parameter
+
+class AdaptiveSin(torch.nn.Module):
+    '''
+    Implementation of soft exponential activation.
+    Shape:
+        - Input: (N, *) where * means, any number of additional
+          dimensions
+        - Output: (N, *), same shape as the input
+    Parameters:
+        - alpha - trainable parameter
+    References:
+        - See related paper:
+        https://arxiv.org/pdf/1602.01321.pdf
+    Examples:
+        >>> a1 = soft_exponential(256)
+        >>> x = torch.randn(256)
+        >>> x = a1(x)
+    '''
+    def __init__(self, alpha = None):
+        '''
+        Initialization.
+        INPUT:
+            - in_features: shape of the input
+            - aplha: trainable parameter
+            aplha is initialized with zero value by default
+        '''
+        super(AdaptiveSin, self).__init__()
+
+        # initialize alpha
+        self.alpha = Parameter(torch.normal(torch.tensor(1.0), torch.tensor(0.1))) # create a tensor out of alpha
+        self.alpha.requiresGrad = True # set requiresGrad to true!
+
+        self.scale = Parameter(torch.normal(torch.tensor(1.0), torch.tensor(0.1)))
+        self.scale.requiresGrad = True # set requiresGrad to true!
+
+        self.translate = Parameter(torch.normal(torch.tensor(0.0), torch.tensor(0.1)))
+        self.translate.requiresGrad = True # set requiresGrad to true!
+
+    def forward(self, x):
+        '''
+        Forward pass of the function.
+        Applies the function to the input elementwise.
+        '''
+        return self.scale * (torch.sin(self.alpha * x + self.translate))