DomainError for some values of the hill exponent

[Azenor]

When using some values of h different from 1.0 or 2.0, we get a DomainError when executing the function simulate(). It seems to occur with the keywords :species, :system, :competitive but not with :nutrients.

Reproducible example :

A = [0 0 0 0 0; 1 0 1 0 0; 1 0 0 0 0; 0 1 0 0 0; 0 0 0 0 0] ;
p = model_parameters(A, productivity = :system, h = 1.2);
s = simulate(p, rand(p[:S]), stop=1000)

Error obtained :

ERROR: DomainError with -6.825133204115963e-9:
Exponentiation yielding a complex result requires a complex argument.
Replace x^y with (x+0im)^y, Complex(x)^y, or similar.

It seems to come from the matrix structure. When removing one link such that A = [0 0 0 0 0; 1 0 1 0 0; 0 0 0 0 0; 0 1 0 0 0; 0 0 0 0 0], it works.

System information

• julia --version
• Pkg.status("BioEnergeticFoodWebs")
• OS and version

[evadelmas]

Hi @Azenor
Biomass values can temporary drop below 0 by up to 1e-6 which causes this DomainError when the hill exponent is 1<h<2. Should be fixed now (on the next branch at least, I'm planning on merging to master in the next few days).