No all vectors here use int to express dimension. It is nothing to do with
sparseness.
On Jun 13, 2011 12:26 AM, "Lance Norskog" <goks...@gmail.com> wrote:
> Ah! So if it was a sparse vector it could be indexed directly. Or the
> mapping could be with a hash-indexed representation as used with
> Lucene vectors.
>
> On Sun, Jun 12, 2011 at 3:43 AM, Sean Owen <sro...@gmail.com> wrote:
>> The keys have to be hashed to be used as int offsets into a vector. While
>> loading the mapping isn't ideal it does only scale as the number of items
>> and users.
>> On Jun 12, 2011 3:47 AM, "Lance Norskog" <goks...@gmail.com> wrote:
>>> The RecommenderJob makes a "side" file which maps a fabricated integer
>>> index to a long ItemID. Why is this needed? Couldn't the
>>> RecommenderJob propagate the long ItemID directly? Note that this
>>> forces all instances of AggregateAndReduceRecommender to load the
>>> entire map. Part of the Map/Reduce rules are 'nothing needs to know
>>> everything'.
>>>
>>> Is this a sparse/dense optimization? If so, have the distributed
>>> algorithms advanced enough to make this indirection unnecessary?
>>>
>>> --
>>> Lance Norskog
>>> goks...@gmail.com
>>
>
>
>
> --
> Lance Norskog
> goks...@gmail.com
