SciML
Handy utility for writing boundary conditions with kwargs
cc @MarcBerliner
This macro takes in a CallWith call (ie u(t, x1, x2) where u was defined like @variables u(..) and defines a method u_kw(;t=t, x1=x1, x2=x2) = u(t, x1, x2) to make it a bit easier to specify boundary conditions.
I haven't tested many cases though. If we wanted to make it a PR, the best thing would probably be defining a new CallWith in Symbolics that would allow for u(t=0) as opposed to needing to call the macro and use u_kw(t=0) but this was the easiest to do.
using Symbolics, Test
function _to_kw(ex)
@assert ex.head == :call
args = ex.args
@assert all(x isa Symbol for x in args)
u = args[1]
xs = args[2:end]
kw_fn_name = Symbol(ex.args[1], "_kw")
kws = []
for arg in xs
kw = Expr(:kw, arg, esc(arg))
push!(kws, kw)
end
params = Expr(:parameters, kws...)
def_call_ex = Expr(:call, kw_fn_name, params)
block_call_ex = Expr(:call, u, xs...)
body = Expr(:block, block_call_ex)
Expr(:function, def_call_ex, body)
end
macro to_kw(ex)
_to_kw(ex)
end
@variables t
N = 2
x = Symbolics.variables(:x, 1:N)
for (i, xi) in enumerate(x)
@eval $(Symbol(:x, i)) = $xi
end
@variables u(..)
@to_kw u(t, x1, x2)
@test isequal(u_kw(t=0), u(0, x1, x2))
@variables foo(..)
@to_kw foo(t, x1, x2)
@test isequal(foo_kw(t=0), foo(0, x1, x2))
Looks interesting, thanks! I may export this. Wouldn't this only work if the variable was called u at present? Would be good to generalise this.
Also by the way, are you @anandijain and @MarcBerliner working together or otherwise affiliated?
We met at Boston Occultists, an organization devoted to corrupting the minds of local youths! Its a hoot and a holler for sure
Anand and I are broadly interested in scientific differential programming and reprogramming the minds of the youth
