Files

We briefly describe the file and folder structure of the package.

Source code

Source code is in the "src" folder:

"src"

• "StructuralEquationModels.jl" defines the module and the exported objects
• "types.jl" defines all abstract types and the basic type hierarchy
• "objective_gradient_hessian.jl" contains methods for computing objective, gradient and hessian values for different model types as well as generic fallback methods
• The four folders "observed", "implied", "loss" and "diff" contain implementations of specific subtypes (for example, the "loss" folder contains a file "ML.jl" that implements the SemML loss function).
• "optimizer" contains connections to different optimization backends (aka methods for sem_fit)
  • "optim.jl": connection to the Optim.jl package
• "frontend" contains user-facing functions
  • "specification" contains functionality for model specification
  • "fit" contains functionality for model assessment, like fit measures and standard errors
• "additional_functions" contains helper functions for simulations, loading artifacts (example data) and various other things

Code for the package extentions can be found in the "ext" folder:

• "SEMNLOptExt" for connection to NLopt.jl.
• "SEMProximalOptExt" for connection to ProximalAlgorithms.jl.

Tests and Documentation

Tests are in the "test" folder, documentation in the "docs" folder.