  In this paper, we study pattern avoidance in weak ascent sequences, giving
some results for patterns of length 3. This is an analogous study to one given
by Duncan and Steingr\'imsson (2011) for ascent sequences. More precisely, we
provide systematically the generating functions for the number of weak ascent
sequences avoiding the patterns $001, 011, 012, 021$, and $102$. Additionally,
we establish bijective connections between pattern-avoiding weak ascent
sequences and other combinatorial objects, such as compositions, upper
triangular 01-matrices, and plane trees.
