I have been using Sundials and (indirectly)
idaDlsBandDQJac for the past several months and it seems to beworking fine. If a band-matrix representation is acceptable in your bvp4c implementation, leveraging Sundials
might be a good idea.
For the next phase of my work, I need a FD jacobian routine for general sparse matrices and,
unfortunately, Sundials doesn't have this. So I've been looking further at the sparse jacobian
paper and implementation by Coleman, et. al. Since my last post, I discovered that this approach
If I find out more, I'll pass it along.
Bill