Model Building (liesel.model)

This is an overview of the most important building blocks for setting up your model graph with liesel.model.

The import path for liesel.model is:

import liesel.model as lsl

The model building workflow in Liesel consists of two steps:

1. Set up the nodes and variables that make up your model.

2. Set up a GraphBuilder, add your root node(s) to it, and call GraphBuilder.build_model() to build your model graph.

Note

This document provides an overview of the most important classes for model building. You find more guidance on how to use them in the respective API documentation and in the tutorials.

Nodes and Variables

The fundamental building blocks of your model graph are given by just three classes and two functions. Each of these building blocks is documented with examples, so make sure to check them out.

Data	A Node subclass that holds constant data.
Calc	A Node subclass that calculates its value based on its inputs nodes.
Dist	A Node subclass that wraps a probability distribution.
obs	Helper function that returns an observed Var.
param	Helper function that returns a parameter Var.

Build and plot your model

The most important class here is the GraphBuilder.

GraphBuilder	A graph builder, used to set up a Model.
Model	A model with a static graph.
plot_vars	Plots the variables of a Liesel model.
plot_nodes	Plots the nodes of a Liesel model.