Possible Bug in Dice (and Jaccard) Function

[momenator]

Hi,

I tried running the dice function on the sample string

select('euler', 'heuser')

and I got 0 instead of 0.444... as specified in the example.

Using another example

select dice('hello there not', 'hello friend what')

It seems that the dice function computes over the words and not the n-grams specified in the comments. Is this the expected behavior?