The package is available at https://github.com/mobius-eng/RadauBVP.jl
I haven't put it into METADATA yet. I would like to improve documentation and add some tests before doing this. However, it is already usable, mostly optimised (except for sparsity, it is coming) and I believe it is the only available free ODE BVP solver for Julia right now (the only other alternative I am aware of is `bvpsol` from ODEInterface.jl, but it is not free and from limited amount of tests I've done, RadauBVP is faster). On Sunday, October 30, 2016 at 8:40:07 PM UTC+2, Chris Rackauckas wrote: > > reshape makes a view, and views are cheap. Don't worry about this. > > BTW, I would love to add a collocation method to JuliaDiffEq. Would you > consider making this a package? > > On Sunday, October 30, 2016 at 3:52:37 AM UTC-7, Alexey Cherkaev wrote: >> >> I'm writing RadauIIA (for now, fixed order 5 with 3 points) method for >> ODE BVP (basically, collocation method). In the process, I construct an >> overall non-linear equation that needs to be solved. It takes "mega-vector" >> x[j] as an argument. However, internally it is more convenient to reshape >> it to y[m,i,n] where m is the index of original ODE vector, i is the index >> of the collocation point on time element (or layer) and n is time element >> index. Also, some inputs to the method (ODE RHS function and BVP function) >> expect z[m]-kind vector. So far I chose to pass a @view of the >> "mega-vector" to them. >> >> The alternatives for reshaping and @view would be: >> >> - Use the inline function or a macro that maps the indices between >> mega-vector and arrays (I've tried it, didn't see any difference in >> performance or memory allocation, but @code_warntype has less "red" spots) >> - Copy relevant pieces of mega-vector into preallocated arrays of >> desired shape. This can also be an alternative for @view. >> >> Is there some kind of rule of thumb where which one would be preferable? >> And are there any high costs associated with @view and reshape? >> >>
