AIBECS `F` is quite slower (5x) than handmade `F`

[briochemc]

[briochemc]

Note to self: Actually it would be nice to be able to create a performant inplace F from the user input of sources and sinks. This might require some code transformation though, so I'm not sure how I would do this.

For example, the user could provide an expression for each term, like

• uptake: -1 / τ * DIP^2 / (DIP + k) * (z ≤ zₑ)
• remin: κ * POP
• geores: (DIPgeo - DIP) / τgeo

and then AIBECS could build an inplace and fused-loop function

function G_DIP!(dDIP, DIP, POP, p)
   @unpack τ, k, zₑ, κ, DIPgeo, τgeo = p # unpack parameters
   dDIP .= @. -1 / τ * DIP^2 / (DIP + k) * (z ≤ zₑ) + κ * POP + (DIPgeo - DIP) / τgeo
end