Skip to content

specification.md

Latest commit

 

History

History
32 lines (23 loc) · 1.27 KB

specification.md

File metadata and controls

32 lines (23 loc) · 1.27 KB

Model specification

Two things can be used to specify a model: a parameter table or ram matrices. You can convert them to each other, and to make your life easier, we also provide a way to get parameter tables from graphs.

This leads to the following chart:

Specification flowchart

You can enter model specification at each point, but in general (and especially if you come from lavaan), it is the easiest to follow the red arrows: specify a graph object, convert it to a prameter table, and use this parameter table to construct your models ( just like we did in A first model):

observed_vars = ...
latent_vars   = ...

graph = @StenoGraph begin
    ...
end

partable = ParameterTable(
    graph,
    latent_vars = latent_vars, 
    observed_vars = observed_vars)

model = Sem(
    specification = partable,
    ...
)

On the following pages, we explain how to enter the specification process at each step, i.e. how to specify models via the Graph interface, the ParameterTable interface, and the RAMMatrices interface. If you have an OpenMx background, and are familiar with their way of specifying structural equation models via RAM matrices, the RAMMatrices interface may be of interest for you.