Twitter co-hashtagging with OpenRefine - twitter

Question

I am using OpenRefine to format some Twitter metadata into a edge list to be read by Gephi.
It works easily if I want to study user-mention associations or user-hashtags associations.
But now I would like to study co-hashtagging, so how often hashtags co-occur in tweets.
To do this in OpenRefine (that I do not know very well) is a bit trickier and I need some help.
My data are in csv, with two columns: user name of the user, comma separated string of hashtags used in the tweet.
To get user-hashtags edge lists with OpenRefine I use "Split multi valued cells" on the hashtags column and then "Fill down" on the user column (very easy).
I do not know how to get hashtag-hashtag edge lists. I can use "Split multi valued cells" on the hashtags column to get a new row for every hashtag mentionned in a tweet. But how do I "fill" the rows so to get all combinations of hashtag-hashtag co-occurrence?
Example:
Data:
User Hashtags
Dario Data mining, R, OpenRefine
Desired result:
Hashtag 1 Hashtag 2
Data mining R
Data mining OpenRefine
R OpenRefine

Answer 1

Also posted on the OpenRefine Google Group:
I think you could do this with a combination of forEach and forRange. Try the following transformation on the cell containing the comma delimited hashtags:
forEachIndex(value.split(","),i,v,forRange(i+1,value.split(",").length(),1,j,v.trim() + "," + value.split(",")[j].trim()).join("|")).join("|")
This should produce a pipe-delimited list of the unique combinations. Then you can use 'split multi-valued cells'

Answer 2

here is my suggestion.
Let's use your example :
User Hashtags
Dario Data mining, R, OpenRefine
1°/ Use the function called "Split multi valued cells in column" on column Hashtags
You should get something like :
User Hashtags
Dario Data mining
R
OpenRefine
2°/ try this transformation on Hashtags column :
if((row.record.cells["Hashtags"].value[-1])==value,value+","+(row.record.cells["Hashtags"].value[0]),value+","+(row.record.cells["Hashtags"].value[-1]))
3°) Split your column in to columns bases on the "," separator.
It works for me.
Edit :
This solution generates a duplicate entry that can be easily removed like this :
Join multi valued cells, using a | separator (for example).
You get something like
1.
Dario
Data mining,Prout|R,Prout|OpenRefine,Prout|Prout,Data mining
2.
Essai
Data mining,R|R,Data mining
Then split cells in columns based on the separator |
finally, remove the first hashtag column.