DiffEqBiological: getting the error "type Symbol has no field head"

Specific Domains Biology, Health, and Medicine
1

I want to make a simple model of enzyme kinetics,but I keep getting some errors
This is what I tried:

rn = @reaction_network begin
k_f, E + S → ES
k_r, ES → E + S
k_p, ES → P
end

and I get the error:

type Symbol has no field head

And when I try this:

rn = @reaction_network begin
(k_f,k_r), E + S ↔ ES
k_p, ES → P

end

I get

syntax: invalid identifier name “–>”

Any help will be highly appreciated.

Thank You in advanced.

2

Julia v1.4?

3

julia version 1.4.2

4

It looks like your hyphen is an elongated hyphen and therefore a different character, which Julia doesn’t recognize as syntax. Perhaps try editing <–> to <->.

5

m = @reaction_model begin
(k_f,k_r), A + B ↔ C
end

This also gives

syntax: invalid identifier name “->”

6

You need to list the parameters at the end like:

rn = @reaction_network begin
k_f, E + S --> ES
k_r, ES --> E + S
k_p, ES --> P
end k_f k_r k_p

If you want to use arrows for reversible reactions they need to be unicode arrows, arrows made from mixing text symbols like <-> don’t work, see https://github.com/SciML/DiffEqBiological.jl/issues/198

1 Like