[MADLIB-1231] Exception in correlation/covariance when mean of a column is null

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: Module: Inferential Statistics
• Assignee: Unassigned
• Reporter: Nikhil
• Created: 01/May/18 19:18
• Updated: 22/May/18 21:24

Description

While working on https://issues.apache.org/jira/browse/MADLIB-1128, we found a bug in the correlation/covariance module.

Repro steps:

create table foo(i int , j int);
insert into foo values(1,NULL);
madlib=# select madlib.correlation('foo','foo_out');
ERROR:  plpy.SPIError: Function "madlib.correlation_transition(double precision[],double precision[],double precision[])": Correlation: Mean vector contains NULL. (UDF_impl.hpp:210)  (entry db 127.0.0.1:15432 pid=46000)
CONTEXT:  Traceback (most recent call last):
  PL/Python function "correlation", line 23, in <module>
    return correlation.correlation(**globals())
  PL/Python function "correlation", line 71, in correlation
  PL/Python function "correlation", line 207, in _populate_output_table
PL/Python function "correlation"
madlib=#

This was introduced in https://issues.apache.org/jira/browse/MADLIB-1166 when we started supporting null values.