Trying to understand cparents.txt in Constituency parsing

[inigo-jauregi]

I have downloaded the SICK data and obtained the dependency and constituency parsing with the fetch_and_preprocess.sh file.

I am now trying to understand what is the information that is generated in the cparents.txt file.
This is an example:

a.txt -> Two dogs are fighting
a.cparents.txt -> 5 5 7 7 6 0 6

If I am not mistaken, from the cparents.txt I should be able to build the parse tree. Is that right? And how would the tree for this example look like?

Thanks for any help in advance

[inigo-jauregi]

Another example:

a.txt -> Two dogs are playing by a tree
a.cparents.txt -> 8 8 10 11 12 13 13 9 0 9 10 11 12

[yeladlouni]

For N tokens, you'll obtain a binary tree of 2N-1 nodes.
To use contituency parsing, you should implement BinaryTreeLSTM which is not ported from the lua original code.

[yalunar]

First assign numbers from 0 to length-1 to the initial sentence in a.txt. These number stands for indices of leaf nodes.
Then substract 1 for all the numbers in a.cparents.txt. Now the number here stands for the index of parent node.
Take the following for example:
a.txt -> Two dogs are fighting | Two ->0,dogs -> 1,are -> 2,fighting -> 3.
a.cparents.txt -> 5 5 7 7 6 0 6 | a.cparents.txt -> 4 4 6 6 5 -1 5

Write cparents as following, the numbers here stands for the indices of a node, -1 stands for the root node:
4 4 6 6 5 -1 5 | parent node index
0 1 2 3 4 5 6 | child node index
the first row is the parent of the second row. For example,4 is the parent of 0 and 1, 6 is the parent of 2 and 3.
leaf nodes are 0,1,2,3.
Now you can have the tree. Hope this help.
@ijauregiCMCRC

[venusafroid]

First assign numbers from 0 to length-1 to the initial sentence in a.txt. These number stands for indices of leaf nodes.
Then substract 1 for all the numbers in a.cparents.txt. Now the number here stands for the index of parent node.
Take the following for example:
a.txt -> Two dogs are fighting | Two ->0,dogs -> 1,are -> 2,fighting -> 3.
a.cparents.txt -> 5 5 7 7 6 0 6 | a.cparents.txt -> 4 4 6 6 5 -1 5

Write cparents as following, the numbers here stands for the indices of a node, -1 stands for the root node:
4 4 6 6 5 -1 5 | parent node index
0 1 2 3 4 5 6 | child node index
the first row is the parent of the second row. For example,4 is the parent of 0 and 1, 6 is the parent of 2 and 3.
leaf nodes are 0,1,2,3.
Now you can have the tree. Hope this help.
@ijauregiCMCRC

Thank you very much !!!!!!
I have been confused for a long time. You answer is really helpful !!!!!

[venusafroid]

First assign numbers from 0 to length-1 to the initial sentence in a.txt. These number stands for indices of leaf nodes.
Then substract 1 for all the numbers in a.cparents.txt. Now the number here stands for the index of parent node.
Take the following for example:
a.txt -> Two dogs are fighting | Two ->0,dogs -> 1,are -> 2,fighting -> 3.
a.cparents.txt -> 5 5 7 7 6 0 6 | a.cparents.txt -> 4 4 6 6 5 -1 5

Write cparents as following, the numbers here stands for the indices of a node, -1 stands for the root node:
4 4 6 6 5 -1 5 | parent node index
0 1 2 3 4 5 6 | child node index
the first row is the parent of the second row. For example,4 is the parent of 0 and 1, 6 is the parent of 2 and 3.
leaf nodes are 0,1,2,3.
Now you can have the tree. Hope this help.
@ijauregiCMCRC
By the way, what the meaning of lines in dparents.txt?

[yalunar]

@venusafroid
Hi! Lines in dparents.txt represent dependency of two words. For example, the sentence is: "Two dogs are wrestling and hugging." The numbers in dparents.txt are parent node idxes of every word:
2 4 4 0 4 4
The i-th number represent the parent node index of the i-th word. 0 represents root node.
Then the parent node of "Two" is "dogs", the parent node of "dogs, are, and, hugging" are "wrestling".