Journal or Book Title
Electronic Journal of Linear Algebra
In this paperthe nonnegative P0-matrix completion problem is considered. It is shown that a pattern for 4 × 4 matrices that includes all diagonal positions has nonnegative P0- completion if and only if its digraph is complete when it has a 4-cycle. It is also shown that any positionally symmetric pattern that includes all diagonal positions and whose graph is an n-cycle has nonnegative P0-completion if and only if n does not equal 4.
Choi, Ji Young; DeAlba, Luz Maria; Hogben, Leslie; Kivunge, Benard M.; Nordstrom, Sandra K.; and Shedenhelm, Mike, "The nonnegative P0-matrix completion problem" (2003). Mathematics Publications. 254.