Thanks! This triplet solution was a miracle
On Monday, February 1, 2016 at 1:46:27 AM UTC-8, Kristoffer Carlsson wrote: > > 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). > >
