Message Passing Neural Network (MPNN)
======================================================





.. code-block:: python

	class DeepPurpose.models.MPNN(nn.Sequential)

`Message Passing Neural Network (MPNN) <https://www.biorxiv.org/content/10.1101/684662v3>`_  
(`Source <https://github.com/kexinhuang12345/DeepPurpose/blob/master/DeepPurpose/models.py#L239>`_) 
encode drug in its graph representation. 


**constructor** create an instance of MPNN class. 

.. code-block:: python

	__init__(self, mpnn_hidden_size, mpnn_depth) 



* **mpnn_hidden_size** (int) - specify dimension of hidden layer in MPNN, e.g,  mpnn_hidden_size = 256.
* **mpnn_depth** (int) - specify depth of MPNN, e.g.,  mpnn_depth = 3. 


**Calling functions** implement the feedforward procedure of MPNN. 


.. code-block:: python

	forward(self, feature)

* **feature** (tuple of length 5)
	* feature[0] (torch.Tensor) - atom-level feature  
	* feature[1] (torch.Tensor) - bond-level feature 
	* feature[2] (torch.Tensor) - neighbor information of every atom
	* feature[3] (torch.Tensor) - neighbor information of every bond 
	* feature[4] (torch.Tensor) - store number of atoms and bonds for each molecule in a batch