> > Given the constructed sys1_ode method is there someway to dynamically > access the captured variables, i.e. those that come from its closure?
I'm not sure I entirely follow, but: you can use the variables p1 and p2 inside the inner function and it will Just Work (scoping rules). But it is not possible to interrogate the closure environment from inside the enclosed function. Also, have you considered macros? They won't help to interrogate the closure environment, but are a much better option for AST rewriting than using code_lowered. On Tue, Oct 14, 2014 at 2:14 PM, Nikolas Tezak <[email protected]> wrote: > Hi all, > > in my research I run numerical simulations (ODEs and SDEs) for circuit > models that can be composed, i.e., > each system has an ode that modifies in-place the elements of an output > array based on the current state variable. > Moreover, dimensionality of each system may vary. > > function sys1_ode(t, x, xdot) > xdot[1] = # some function of x, t > xdot[2] = # some other function of x, t > end > > > function sys2_ode(t, x, xdot) > xdot[1] = # some expression with x, t > xdot[2] = # some other expression with x, t > xdot[3] = # some other expression with x, t > end > > > What I would like to do is use metaprogramming to construct a combined ode > for both systems where the state vectors are just stacked. For each system > I compute the offset within the state vector (0 for sys1 and 2 for sys2) > and then modify and recombine the function code as follows > > function sys12_ode(t, x, xdot) > xdot[1+0] = # some expression with x[1:2], t > xdot[2+0] = # some other expression with x[1:2], t > xdot[1+2] = # some expression with x[1+2:3+2], t > > xdot[2+2] = # some expression with x[1+2:3+2], t > xdot[3+2] = # some expression with x[1+2:3+2], t > > end > > > So far, that would seem to be quite straightforward and I think I could > get this working by calling code_lowered(sys1_ode) and using the rewritten > output to construct an AST for the combined function. > > The difficulty now arises when my sys1 and sys2 odes are defined with some > internal parameters that are not passed as an argument but rather through a > closure from the surrounding scope, i.e. I have some ode factory: > > funcion make_sys1_ode(p1, p2) > function sys1_ode(t, x, xdot) > xdot[1] = # some expression with x, t AND p1, p2 > xdot[2] = # some expression with of x, t AND p1, p2 > end > sys1_ode > end > > Given the constructed sys1_ode method is there someway to dynamically > access the captured variables, i.e. those that come from its closure? > Otherwise, I suppose I could resort to passing parameters via an extra ODE > argument, but it would be super nice if I could avoid this. > The reason why I am trying to implement things this way is to speed up ODE > evaluation for very large complex (i.e. nested) circuits by expanding out > all ODE bodies into a single function. > > I hope this write-up makes sense. > Thanks, > Nik > >
