How can I code a constraint like this in JUMP? Suppose i,j,k,m are indices and capital letters associated with them are set, like J. x_{i,j,k,m'} + sum((j in J, k in K), y_{j,k,m})<= z_{i,m} for al...

Cairo provides read_from_png, but returns value of a special type CairoSurfaceBase, which is hard to operate, so I choose Matrix{RGB}(the thing ImageIO returns). Cairo does provide something called se...

I got an apparently quite common Julia error when trying to use AD with forward.diff. The error messages vary a bit (sometimes matching function name sometimes Float64) MethodError: no method matching...

I am trying to parallelize the creation of a sparse matrix in Julia. Inspired by this post this post I am trying this: using Distributed addprocs(4) @everywhere using DistributedArrays rows = [Int[] ...