At computer now. Something like this:
function f(k)
I, J, V = Int[], Int[], Float64[]
for i = 1:k
idxs = (i-1)*2 + 1:i*2
for i in idxs, j in idxs
push!(I, i)
push!(J, j)
push!(V, rand())
end
end
return sparse(I,J,V)
end
@time f(10000)
0.001932 seconds (71 allocations: 4.986 MB)
On Monday, February 1, 2016 at 9:25:22 AM UTC+1, Kristoffer Carlsson wrote:
>
> Create the vectors I J V which holds the nonzero rows, columns and values
> respectively and then call sparse(I, J, V).
