Put parenthesis around each 4th term of so. There’s 36 terms nested deep in * which causes an issue. Parse 1 + 2 + 3 as +(1, +(2, 3)) · Issue #34999 · JuliaLang/julia · GitHub is the proposed fix.
For now, an automated way to work around this is to use ModelingToolkit to regenerate your function:
using ModelingToolkit, StaticArrays
@variables t u[1:7](t) p[1:3]
@derivatives D'~t
function Nodes(u,p,t) #equations to be solved. For large N, they get very long and ugly
A1=((9*((p[3])^2/2)-p[2]/2*abs2(p[1]))*u[1]-p[2]/2*(p[1])^2*conj(u[7]) - (p[2]/2)*(2*p[1]*u[1]*conj(u[4])+conj(p[1])*u[1]*u[4]+2*p[1]*u[2]*conj(u[5])+conj(p[1])*u[2]*u[3]+2*p[1]*u[3]*conj(u[6])+conj(p[1])*u[3]*u[2]+2*p[1]*u[4]*conj(u[7])+conj(p[1])*u[4]*u[1] + u[1]*conj(u[1])*u[1]+u[1]*conj(u[2])*u[2]+u[2]*conj(u[2])*u[1]+u[1]*conj(u[3])*u[3]+u[2]*conj(u[3])*u[2]+u[3]*conj(u[3])*u[1]+u[1]*conj(u[4])*u[4]+u[2]*conj(u[4])*u[3]+u[3]*conj(u[4])*u[2]+u[4]*conj(u[4])*u[1]+u[1]*conj(u[5])*u[5]+u[2]*conj(u[5])*u[4]+u[3]*conj(u[5])*u[3]+u[4]*conj(u[5])*u[2]+u[5]*conj(u[5])*u[1]+u[1]*conj(u[6])*u[6]+u[2]*conj(u[6])*u[5]+u[3]*conj(u[6])*u[4]+u[4]*conj(u[6])*u[3]+u[5]*conj(u[6])*u[2]+u[6]*conj(u[6])*u[1]+u[1]*conj(u[7])*u[7]+u[2]*conj(u[7])*u[6]+u[3]*conj(u[7])*u[5]+u[4]*conj(u[7])*u[4]+u[5]*conj(u[7])*u[3]+u[6]*conj(u[7])*u[2]+u[7]*conj(u[7])*u[1]))/im
A2=((4*((p[3])^2/2)-p[2]/2*abs2(p[1]))*u[2]-p[2]/2*(p[1])^2*conj(u[6]) - (p[2]/2)*(2*p[1]*u[1]*conj(u[3])+conj(p[1])*u[1]*u[5]+2*p[1]*u[2]*conj(u[4])+conj(p[1])*u[2]*u[4]+2*p[1]*u[3]*conj(u[5])+conj(p[1])*u[3]*u[3]+2*p[1]*u[4]*conj(u[6])+conj(p[1])*u[4]*u[2]+2*p[1]*u[5]*conj(u[7])+conj(p[1])*u[5]*u[1] + u[1]*conj(u[1])*u[2]+u[2]*conj(u[1])*u[1]+u[1]*conj(u[2])*u[3]+u[2]*conj(u[2])*u[2]+u[3]*conj(u[2])*u[1]+u[1]*conj(u[3])*u[4]+u[2]*conj(u[3])*u[3]+u[3]*conj(u[3])*u[2]+u[4]*conj(u[3])*u[1]+u[1]*conj(u[4])*u[5]+u[2]*conj(u[4])*u[4]+u[3]*conj(u[4])*u[3]+u[4]*conj(u[4])*u[2]+u[5]*conj(u[4])*u[1]+u[1]*conj(u[5])*u[6]+u[2]*conj(u[5])*u[5]+u[3]*conj(u[5])*u[4]+u[4]*conj(u[5])*u[3]+u[5]*conj(u[5])*u[2]+u[6]*conj(u[5])*u[1]+u[1]*conj(u[6])*u[7]+u[2]*conj(u[6])*u[6]+u[3]*conj(u[6])*u[5]+u[4]*conj(u[6])*u[4]+u[5]*conj(u[6])*u[3]+u[6]*conj(u[6])*u[2]+u[7]*conj(u[6])*u[1]+u[2]*conj(u[7])*u[7]+u[3]*conj(u[7])*u[6]+u[4]*conj(u[7])*u[5]+u[5]*conj(u[7])*u[4]+u[6]*conj(u[7])*u[3]+u[7]*conj(u[7])*u[2]))/im
A3=((1*((p[3])^2/2)-p[2]/2*abs2(p[1]))*u[3]-p[2]/2*(p[1])^2*conj(u[5]) - (p[2]/2)*(2*p[1]*u[1]*conj(u[2])+conj(p[1])*u[1]*u[6]+2*p[1]*u[2]*conj(u[3])+conj(p[1])*u[2]*u[5]+2*p[1]*u[3]*conj(u[4])+conj(p[1])*u[3]*u[4]+2*p[1]*u[4]*conj(u[5])+conj(p[1])*u[4]*u[3]+2*p[1]*u[5]*conj(u[6])+conj(p[1])*u[5]*u[2]+2*p[1]*u[6]*conj(u[7])+conj(p[1])*u[6]*u[1] + u[1]*conj(u[1])*u[3]+u[2]*conj(u[1])*u[2]+u[3]*conj(u[1])*u[1]+u[1]*conj(u[2])*u[4]+u[2]*conj(u[2])*u[3]+u[3]*conj(u[2])*u[2]+u[4]*conj(u[2])*u[1]+u[1]*conj(u[3])*u[5]+u[2]*conj(u[3])*u[4]+u[3]*conj(u[3])*u[3]+u[4]*conj(u[3])*u[2]+u[5]*conj(u[3])*u[1]+u[1]*conj(u[4])*u[6]+u[2]*conj(u[4])*u[5]+u[3]*conj(u[4])*u[4]+u[4]*conj(u[4])*u[3]+u[5]*conj(u[4])*u[2]+u[6]*conj(u[4])*u[1]+u[1]*conj(u[5])*u[7]+u[2]*conj(u[5])*u[6]+u[3]*conj(u[5])*u[5]+u[4]*conj(u[5])*u[4]+u[5]*conj(u[5])*u[3]+u[6]*conj(u[5])*u[2]+u[7]*conj(u[5])*u[1]+u[2]*conj(u[6])*u[7]+u[3]*conj(u[6])*u[6]+u[4]*conj(u[6])*u[5]+u[5]*conj(u[6])*u[4]+u[6]*conj(u[6])*u[3]+u[7]*conj(u[6])*u[2]+u[3]*conj(u[7])*u[7]+u[4]*conj(u[7])*u[6]+u[5]*conj(u[7])*u[5]+u[6]*conj(u[7])*u[4]+u[7]*conj(u[7])*u[3]))/im
A4=((-p[2]/2*abs2(p[1]))*u[4]-p[2]/2*(p[1])^2*conj(u[4]) - (p[2]/2)*(2*p[1]*u[1]*conj(u[1])+conj(p[1])*u[1]*u[7]+2*p[1]*u[2]*conj(u[2])+conj(p[1])*u[2]*u[6]+2*p[1]*u[3]*conj(u[3])+conj(p[1])*u[3]*u[5]+2*p[1]*u[4]*conj(u[4])+conj(p[1])*u[4]*u[4]+2*p[1]*u[5]*conj(u[5])+conj(p[1])*u[5]*u[3]+2*p[1]*u[6]*conj(u[6])+conj(p[1])*u[6]*u[2]+2*p[1]*u[7]*conj(u[7])+conj(p[1])*u[7]*u[1] + u[1]*conj(u[1])*u[4]+u[2]*conj(u[1])*u[3]+u[3]*conj(u[1])*u[2]+u[4]*conj(u[1])*u[1]+u[1]*conj(u[2])*u[5]+u[2]*conj(u[2])*u[4]+u[3]*conj(u[2])*u[3]+u[4]*conj(u[2])*u[2]+u[5]*conj(u[2])*u[1]+u[1]*conj(u[3])*u[6]+u[2]*conj(u[3])*u[5]+u[3]*conj(u[3])*u[4]+u[4]*conj(u[3])*u[3]+u[5]*conj(u[3])*u[2]+u[6]*conj(u[3])*u[1]+u[1]*conj(u[4])*u[7]+u[2]*conj(u[4])*u[6]+u[3]*conj(u[4])*u[5]+u[4]*conj(u[4])*u[4]+u[5]*conj(u[4])*u[3]+u[6]*conj(u[4])*u[2]+u[7]*conj(u[4])*u[1]+u[2]*conj(u[5])*u[7]+u[3]*conj(u[5])*u[6]+u[4]*conj(u[5])*u[5]+u[5]*conj(u[5])*u[4]+u[6]*conj(u[5])*u[3]+u[7]*conj(u[5])*u[2]+u[3]*conj(u[6])*u[7]+u[4]*conj(u[6])*u[6]+u[5]*conj(u[6])*u[5]+u[6]*conj(u[6])*u[4]+u[7]*conj(u[6])*u[3]+u[4]*conj(u[7])*u[7]+u[5]*conj(u[7])*u[6]+u[6]*conj(u[7])*u[5]+u[7]*conj(u[7])*u[4]))/im
A5=((1*((p[3])^2/2)-p[2]/2*abs2(p[1]))*u[5]-p[2]/2*(p[1])^2*conj(u[3]) - (p[2]/2)*(2*p[1]*u[2]*conj(u[1])+conj(p[1])*u[2]*u[7]+2*p[1]*u[3]*conj(u[2])+conj(p[1])*u[3]*u[6]+2*p[1]*u[4]*conj(u[3])+conj(p[1])*u[4]*u[5]+2*p[1]*u[5]*conj(u[4])+conj(p[1])*u[5]*u[4]+2*p[1]*u[6]*conj(u[5])+conj(p[1])*u[6]*u[3]+2*p[1]*u[7]*conj(u[6])+conj(p[1])*u[7]*u[2] + u[1]*conj(u[1])*u[5]+u[2]*conj(u[1])*u[4]+u[3]*conj(u[1])*u[3]+u[4]*conj(u[1])*u[2]+u[5]*conj(u[1])*u[1]+u[1]*conj(u[2])*u[6]+u[2]*conj(u[2])*u[5]+u[3]*conj(u[2])*u[4]+u[4]*conj(u[2])*u[3]+u[5]*conj(u[2])*u[2]+u[6]*conj(u[2])*u[1]+u[1]*conj(u[3])*u[7]+u[2]*conj(u[3])*u[6]+u[3]*conj(u[3])*u[5]+u[4]*conj(u[3])*u[4]+u[5]*conj(u[3])*u[3]+u[6]*conj(u[3])*u[2]+u[7]*conj(u[3])*u[1]+u[2]*conj(u[4])*u[7]+u[3]*conj(u[4])*u[6]+u[4]*conj(u[4])*u[5]+u[5]*conj(u[4])*u[4]+u[6]*conj(u[4])*u[3]+u[7]*conj(u[4])*u[2]+u[3]*conj(u[5])*u[7]+u[4]*conj(u[5])*u[6]+u[5]*conj(u[5])*u[5]+u[6]*conj(u[5])*u[4]+u[7]*conj(u[5])*u[3]+u[4]*conj(u[6])*u[7]+u[5]*conj(u[6])*u[6]+u[6]*conj(u[6])*u[5]+u[7]*conj(u[6])*u[4]+u[5]*conj(u[7])*u[7]+u[6]*conj(u[7])*u[6]+u[7]*conj(u[7])*u[5]))/im
A6=((4*((p[3])^2/2)-p[2]/2*abs2(p[1]))*u[6]-p[2]/2*(p[1])^2*conj(u[2]) - (p[2]/2)*(2*p[1]*u[3]*conj(u[1])+conj(p[1])*u[3]*u[7]+2*p[1]*u[4]*conj(u[2])+conj(p[1])*u[4]*u[6]+2*p[1]*u[5]*conj(u[3])+conj(p[1])*u[5]*u[5]+2*p[1]*u[6]*conj(u[4])+conj(p[1])*u[6]*u[4]+2*p[1]*u[7]*conj(u[5])+conj(p[1])*u[7]*u[3] + u[1]*conj(u[1])*u[6]+u[2]*conj(u[1])*u[5]+u[3]*conj(u[1])*u[4]+u[4]*conj(u[1])*u[3]+u[5]*conj(u[1])*u[2]+u[6]*conj(u[1])*u[1]+u[1]*conj(u[2])*u[7]+u[2]*conj(u[2])*u[6]+u[3]*conj(u[2])*u[5]+u[4]*conj(u[2])*u[4]+u[5]*conj(u[2])*u[3]+u[6]*conj(u[2])*u[2]+u[7]*conj(u[2])*u[1]+u[2]*conj(u[3])*u[7]+u[3]*conj(u[3])*u[6]+u[4]*conj(u[3])*u[5]+u[5]*conj(u[3])*u[4]+u[6]*conj(u[3])*u[3]+u[7]*conj(u[3])*u[2]+u[3]*conj(u[4])*u[7]+u[4]*conj(u[4])*u[6]+u[5]*conj(u[4])*u[5]+u[6]*conj(u[4])*u[4]+u[7]*conj(u[4])*u[3]+u[4]*conj(u[5])*u[7]+u[5]*conj(u[5])*u[6]+u[6]*conj(u[5])*u[5]+u[7]*conj(u[5])*u[4]+u[5]*conj(u[6])*u[7]+u[6]*conj(u[6])*u[6]+u[7]*conj(u[6])*u[5]+u[6]*conj(u[7])*u[7]+u[7]*conj(u[7])*u[6]))/im
A7=((9*((p[3])^2/2)-p[2]/2*abs2(p[1]))*u[7]-p[2]/2*(p[1])^2*conj(u[1]) - (p[2]/2)*(2*p[1]*u[4]*conj(u[1])+conj(p[1])*u[4]*u[7]+2*p[1]*u[5]*conj(u[2])+conj(p[1])*u[5]*u[6]+2*p[1]*u[6]*conj(u[3])+conj(p[1])*u[6]*u[5]+2*p[1]*u[7]*conj(u[4])+conj(p[1])*u[7]*u[4] + u[1]*conj(u[1])*u[7]+u[2]*conj(u[1])*u[6]+u[3]*conj(u[1])*u[5]+u[4]*conj(u[1])*u[4]+u[5]*conj(u[1])*u[3]+u[6]*conj(u[1])*u[2]+u[7]*conj(u[1])*u[1]+u[2]*conj(u[2])*u[7]+u[3]*conj(u[2])*u[6]+u[4]*conj(u[2])*u[5]+u[5]*conj(u[2])*u[4]+u[6]*conj(u[2])*u[3]+u[7]*conj(u[2])*u[2]+u[3]*conj(u[3])*u[7]+u[4]*conj(u[3])*u[6]+u[5]*conj(u[3])*u[5]+u[6]*conj(u[3])*u[4]+u[7]*conj(u[3])*u[3]+u[4]*conj(u[4])*u[7]+u[5]*conj(u[4])*u[6]+u[6]*conj(u[4])*u[5]+u[7]*conj(u[4])*u[4]+u[5]*conj(u[5])*u[7]+u[6]*conj(u[5])*u[6]+u[7]*conj(u[5])*u[5]+u[6]*conj(u[6])*u[7]+u[7]*conj(u[6])*u[6]+u[7]*conj(u[7])*u[7]))/im
@SVector [A1, A2, A3, A4, A5, A6, A7]
end
rhs = Nodes(u,p,t)
eqs = @. D(u) ~ rhs
sys = ODESystem(Array(eqs),t,u,p)
Nodes2 = generate_function(sys,expression=Val{false})[1]
N = 7; g = 0.1; psi = 0.2
Analytic_N=Int64(floor((N-1)/2))
k=sqrt(g*psi) #defining parameters
p = [psi,g,k]
u1=[0.0+0.0*im for i in 1:N] # simple initial conditions
u1[Int64((N-1)/2)]=1.0+0.0*im
u1[Int64((N-1)/2)+1]=0.0+0.0*im
u1[Int64((N-1)/2)+2]=1.0+0.0*im
u0=SVector{N}(u1)
using BenchmarkTools
@btime Nodes(u0,p,0.0)
@btime Nodes2(u0,p,0.0)
5.920 μs (313 allocations: 14.27 KiB)
578.571 ns (2 allocations: 272 bytes)
That’s a whole order of magnitude faster. FWIW, it seems like you might be programmatically generating these equations, and ModelingToolkit might be a nice way to do that which will also automatically parallelize if you use the parallelism options. This may be worth thinking about as the complexity grows.