c_0 should be is a zero vector

[Rah]

In Abigail See's paper, it says that c_0 is a zero vector, but based on the following line, c_0 in your code is equivalent to a_0 or maybe I'm missing something.

pointer_summarizer/training_ptr_gen/model.py

Line 122 in 454a2f6

 coverage = coverage + attn_dist 

[Atul Kumar]

c_0 is zero vector only in case of training. For decoding (self.training == False) c_0 is same as a_0 as you mention.
Here is the relevant code in Abigail See's repo
https://github.com/abisee/pointer-generator/blob/a7317f573d01b944c31a76bde7218bcfc890ef6a/attention_decoder.py#L140

[Rah]

you're right thanks.