[SYSTEMDS-1008] RemoveEmtpy w/ selection vector and nnz=0 produces wrong output

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: SystemML 0.11
• Assignee: Matthias Boehm
• Reporter: Matthias Boehm
• Created: 03/Oct/16 22:09
• Updated: 04/Oct/16 18:36
• Resolved: 04/Oct/16 18:36

Description

RemoveEmtpy with selection vector always has to respect the selection vector over the actual data. If the input matrix has no non-zero entries, however, we currently produce incorrect results of an empty row/column output vector.

For example, the following script should print nrow (A) = 10, nrow (C) = 10 but prints nrow (A) = 10, nrow (C) = 1.

A = matrix (0, rows = 10, cols = 1);
B = matrix (1, rows = 10, cols = 1);
C = removeEmpty (target = A, margin = "rows", select = B);
print ("nrow (A) = " + nrow (A) + ",  nrow (C) = " + nrow (C));

Thanks to ae2015 for catching this.