As I recall, it is in there in the math, but doesn't appear as an explicit
term in the computation. You don't actually materialize the 0 input or the
"c=1" corresponding to them.
Or: do you have a computation that agrees with the paper but not this code?
Put another way, none of this would
Hi Sean,
I agree there is no need for that if the implementation actually assigns
c=1 for all missing ratings but from the current implementation of ALS, I
don't think it is doing that.
The idea is that for missing ratings, they are assigned to c=1 (in the
paper) and they do contribute to the
That doesn't mean this 0 value is literally included in the input. There's
no need for that.
On Tue, Dec 6, 2016 at 4:24 AM Jerry Lam wrote:
> Hi Sean,
>
> I'm referring to the paper (http://yifanhu.net/PUB/cf.pdf) Section 2:
> " However, with implicit feedback it would be
Hi Sean,
I'm referring to the paper (http://yifanhu.net/PUB/cf.pdf) Section 2:
" However, with implicit feedback it would be natural to assign values to
all rui variables. If no action was observed rui is set to zero, thus
meaning in our examples zero watching time, or zero purchases on record."
What are you referring to in what paper? implicit input would never
materialize 0s for missing values.
On Tue, Dec 6, 2016 at 3:42 AM Jerry Lam wrote:
> Hello spark users and developers,
>
> I read the paper from Yahoo about CF with implicit feedback and other
> papers
Hello spark users and developers,
I read the paper from Yahoo about CF with implicit feedback and other
papers using implicit feedbacks. Their implementation require to set the
missing rating with 0. That is for unobserved ratings, the confidence for
those is set to 1 (c=1). Therefore, the matrix