LDA error question

[Frank McQuillan <fm...@pivotal.io>]

Here is an error that came in from a MADlib user.  I am cutting an pasting
his question below:

madpack.py : ERROR : Failed executing
/tmp/madlib.5KsapX/lda/test/lda.sql_in.tmp
madpack.py : ERROR : Check the log at
/tmp/madlib.5KsapX/lda/test/lda.sql_in.log
TEST CASE RESULT|Module: lda|lda.sql_in|FAIL|Time: 6668 milliseconds

Tailing that log file yields:

                               lda_predict
--------------------------------------------------------------------------
 (lda_pred_2,"per-doc topic distribution and per-word topic assignments")
(1 row)

SELECT lda_get_perplexity(
    'lda_model',
    'lda_pred');
 lda_get_perplexity
--------------------
      20.2985761955
(1 row)

SELECT __lda_util_index_sort(array[1, 4, 2, 3]);
 __lda_util_index_sort
-----------------------
 {1,3,4,2}
(1 row)

SELECT __lda_util_transpose(array[[1, 2, 3],[4, 5, 6]]);
 __lda_util_transpose
----------------------
 {{1,4},{2,5},{3,6}}
(1 row)

SELECT assert(count(*) = 2, 'Wrong answer: __lda_util_unnest_transpose()')
FROM
(
    SELECT __lda_util_unnest_transpose(array[1, 2, 0, 4, 5, 0]::bigint[],
3, 2)
) subq;
psql:/tmp/madlib.5KsapX/lda/test/lda.sql_in.tmp:194: ERROR:  Failed
assertion: Wrong answer: __lda_util_unnest_transpose()