I have a 2x2 matrix
a = [1 2
3 4]
2×2 Array{Int64,2}:
1 2
3 4
and want to add a row of all 0s. I can just do this:
vcat(0, a)
3×2 Array{Int64,2}:
0 0
1 2
3 4
The 0 gets recycled and fills up the entire first row. To me (coming from R) this makes sense.
What does not make sense to me is the following:
hcat(0, a)
ERROR: DimensionMismatch("mismatch in dimension 1 (expected 1 got 2)")
Anyone got an explanation?