Fix bugs in 0.2 (#344)

* Fix some bugs

pina/label_tensor.py

@@ -5,7 +5,6 @@ import torch
 from torch import Tensor
 
 
-
 # class LabelTensor(torch.Tensor):
 #     """Torch tensor with a label for any column."""
 
@@ -307,13 +306,13 @@ from torch import Tensor
 #             s = "no labels\n"
 #         s += super().__str__()
 #         return s
-
 def issubset(a, b):
     """
     Check if a is a subset of b.
     """
     return set(a).issubset(set(b))
 
+
 class LabelTensor(torch.Tensor):
     """Torch tensor with a label for any column."""
 
@@ -403,6 +402,10 @@ class LabelTensor(torch.Tensor):
         return LabelTensor(new_tensor, label_to_extract)
         
     def __str__(self):
+        """
+        returns a string with the representation of the class
+        """
+
         s = ''
         for key, value in self.labels.items():
             s += f"{key}: {value}\n"
@@ -431,4 +434,32 @@ class LabelTensor(torch.Tensor):
 
     @property
     def dtype(self):
-        return super().dtype
+        return super().dtype
+
+
+    def to(self, *args, **kwargs):
+        """
+        Performs Tensor dtype and/or device conversion. For more details, see
+        :meth:`torch.Tensor.to`.
+        """
+        tmp = super().to(*args, **kwargs)
+        new = self.__class__.clone(self)
+        new.data = tmp.data
+        return new
+
+
+    def clone(self, *args, **kwargs):
+        """
+        Clone the LabelTensor. For more details, see
+        :meth:`torch.Tensor.clone`.
+
+        :return: A copy of the tensor.
+        :rtype: LabelTensor
+        """
+        # # used before merging
+        # try:
+        #     out = LabelTensor(super().clone(*args, **kwargs), self.labels)
+        # except:
+        #     out = super().clone(*args, **kwargs)
+        out = LabelTensor(super().clone(*args, **kwargs), self.labels)
+        return out