Is preallocation possible for repeated calculation of trajectory of a discrete model (DynamicalSystems.jl)?

General Usage
1

I need to analyze the following discrete model in r-k parametric space,

function test_difference_eq(x,par,n)
   r, k = par
   a = 5.0; mu = 0.5; d = 0.2;
   dx = x[1]*exp(r*(1-x[1]/k)-x[2]/(a+x[1]^2))
   dy = x[2]*exp(mu*x[1]/(a+x[1]^2)-d)
   return @SVector [dx, dy]
end

I used DynamicalSystems.jl and calculated the trajectories inside two for loops (nested):

for i = 1:xpts         
     for j = 1:ypts
          set_parameter!(ds, [par1[i], par2[j]])
          tr = trajectory(ds, NIter; Ttr=NTr)
          # do the analysis here on tr[:,1] 
          # for example, period = seqper(tr[:,1])
     end
end

Can tr be preallocated? Also tr[:,1] makes its own allocation. @view tr[:,1] doesn’t work with Dataset used in DynamicalSystems.jl

Any help?

Thanks in advance.

Full code can be found here.

2

ask people who maintain this package

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3

I don’t know where should I ask. Can anyone show me?

Alternatively, can I extend the package by adding another version of trajectory that accepts an array for solution and then modifies it, Will it be helpful?

4

For packages located on github, you can usually open an issue on their repository (found here) and in it ask about adding a function trajectory! that takes a preallocated vector as input.

Yeah, that should be possible by defining DynamicalSystems.trajectory!. If you add that function to the issue (or directly create a PR, with it being added in the appropriate place) it will probably be appreciated by the maintainers.

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