Ahmed, if you are getting this, in all cases people talked about it it meant their problem was too small. If A has m x n geometry, then it must be true that k+p<=min(m,n).
Another possible reason is if height of blocks of A crerated in the mappers are less than k+p. In practice we yet to see a problem that actually may ever run into condition (although it is definitely possible if you occasionally have very dense very large row vectors so they take up enough space to create split block height problem). If it is indeed split block height problem, then the remedy is to increase split size either by hadoop parameter or (i think) one of the SSVD command line parameters. Although like i said nobody yet ran into block height deficiency problem yet so i have no knowledge of verified resolution of this problem by means of manipulating hadoop parameter setup in Mahout. -d On Sun, Oct 7, 2012 at 2:16 PM, Ahmed Elgohary <[email protected]> wrote: > Hi, > > Can someone list all the constrains on the parameters (k,p &aBlockRows) > that should be satisfied in order for the Q-job in ssvd to work fine? I > tried many values, made sure that (k+p<=m & k+p<=n & p is in the range 20 > .. 200). but I am still getting the errors: "Givens thin QR: must be true: > m>=n" or ""new m can't be less than n". > > thanks, > > --ahmed
