On Wed, 2015-09-30 at 13:04, Kristoffer Carlsson <kcarlsso...@gmail.com> wrote:
> Because it would imo raise the barrier to use a lot. A new type is sort of
> viral in the sense that if you use it, it is likely that you should use the
> type everywhere you are using Voigt Tensors.
>
> I want this to be directly usable even if you have written all your FEM
> code with Vector{Float64} and just want to use this in a few places.I can see this, kinda. But if you go the macro-route then instead of just changing the type in one place you now need to annotate the usages in many places. > # Constructs the final expression > function vexp(e::Expr) > exps = initiate(e::Expr) > sub!(e) > f_exp = :() > for exp in exps > f_exp = quote > $f_exp > $exp > end > end > f_exp = quote > $f_exp > $e > end > return f_exp > end Yes, this will create nested begin-end blocks. also note that `:().head==:tuple`. Try: exps = initiate(e::Expr) f_exp = quote end append!(f_exp.args, exps) push!(f_exp.args, e) > macro v(e) > vexp(e) > end > > > > On Wednesday, September 30, 2015 at 11:30:04 AM UTC+2, Mauro wrote: >> >> I see. Why are you not making a new type to allow getindex overloading? >> That would be more work but maybe cleaner? >> >> On Wed, 2015-09-30 at 11:10, Kristoffer Carlsson <kcarl...@gmail.com >> <javascript:>> wrote: >> > I am not sure that I want Ragged Arrays, In my code I have symmetric 3x3 >> > matrices stored as vectors of length 6 and unsymmetric 3x3 matrices >> stored >> > as vectors of length 9. >> > >> > As I know you do some FEM Mauro I can describe my problem more >> > specifically. I am writing a package do more easily deal with Voigt >> tensors >> > and I want to add the option of accessing them just like they where >> > matrices. Since different people use different order of their indices I >> > want the user to be able to set what order the offdiagonal indices will >> be >> > stored in the Voigt vector. I have a global state in my module that maps >> > [i,j] -> k where k is the index in the vector. >> > >> > I will try your macro now! Thanks a lot for the help. >> > >> > >> > >> > >> > On Wednesday, September 30, 2015 at 10:57:14 AM UTC+2, Mauro wrote: >> >> >> >> > Hello everyone, >> >> > >> >> > I am trying to write a macro that transforms an expression like: >> >> > >> >> > @foo v[1,2] + v[1,3]*v[2,4] -> v[I[1,2]] + v[I[1,3]]*v[I[2,4]] >> >> > >> >> > Basically, for each getindex I want to insert a lookup of the index >> in >> >> some >> >> > other variable. >> >> > The reason for this is that I am working with matrices encoded as >> >> vectors >> >> > and I want to still call them like matrices. The "I" vector in the >> code >> >> > is the lookup from two dimensional indexing to one dimensional. >> >> > >> >> > v is just a normal Vector so I cannot extend getindex which is why I >> >> > thought a macro would be the cleanest solution. >> >> > >> >> > I am a bit lost how to start so any help would be appreciated. >> >> >> >> Sounds like you may want to use >> >> https://github.com/mbauman/RaggedArrays.jl (or my more primitive >> >> Ragged.jl) >> >> >> >> If not, this may work: >> >> >> >> function sub!(e::Expr) >> >> if e.head==:ref >> >> for a in e.args >> >> sub!(a) >> >> end >> >> newe = :($(e.args[1])[I[$(e.args[2:end]...)]]) >> >> e.args = newe.args >> >> else >> >> for a in e.args >> >> sub!(a) >> >> end >> >> end >> >> e >> >> end >> >> sub!(s) = s >> >> >> >> e = :(v[1,2] + v[1,3]*v[2,4]) >> >> sub!(e) >> >> macro foo(e) >> >> sub!(e) >> >> end >> >> >>
