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FRED Modeling Language Guide

Welcome to FRED, the Framework for Reconstructing Epidemiological Dynamics. This document provides detailed information on using the FRED Modeling Language™ to create FRED programs. This guide is focused on the syntax and structure of a FRED program. For information on compiling and executing FRED programs, please see the documentation for the FRED Modeling Platform™.

The following chapters will provide details on the FRED Modeling Language and the components of a FRED model, including:

• Chapter 1: Introduction
  • Hello FRED
  • A First Simulation Model
  • The FRED Simulation Cycle
  • Declarative Programming in FRED
• Chapter 2: FRED Models
  • The Structure of a FRED Program
  • The Simulation Block
  • The Comment Block
• Chapter 3: Agents
  • Individual Agents
  • Group Agents
  • The Meta Agent
  • Synthetic Populations
• Chapter 4: Conditions and States
  • Conditions
  • States
• Chapter 5: Variables
  • Variables Types
  • Shared & Agent Variables
  • The Variables Block
  • Startup Blocks
  • Local Variables
• Chapter 6: Read-Only Variables
  • Shared Read-Only Variables
  • Agent Read-Only Variables
• Chapter 7: Expression and Functions
  • Expressions
  • Numerical Operators
  • Input Functions
  • Mathematical Functions
  • Statistical Distribution Functions
  • Date and Time Functions
  • Functions on Conditions
  • Functions on Groups
  • Functions on Other Agents
  • Functions on Lists
  • Functions on Tables
• Chapter 8: Predicates
  • Numeric Predicates
  • Predicates on Lists
  • Predicates on Agents
  • Predicates on Conditions
  • Predicates on Mixing Groups
  • Predicates on the Date
  • Predicates on Files
• Chapter 9: Mixing Groups
  • Declaring a Mixing Group
  • Places
  • Place Schedules
  • Containers
  • Networks
• Chapter 10: Action Rules
  • Actions by Ordinary Agents
  • Actions on Variables
  • Actions on Conditions
  • Actions on Groups
  • Actions on Other Agents
  • Actions on Self
  • Actions by Group Agents
  • Actions by the Meta Agent
  • Actions Generating Output
  • Control Structures for Actions
• Chapter 11: Wait Rules
  • The until() Function
  • Multiple Wait Rules
  • Zero-duration Wait Rules
• Chapter 12: State Transitions
  • Transition Rules
  • State Transitions
  • Multiple Probabilistic Rules
  • Cautions
  • Example: Using Rules to Represent Health Risks
  • Concurrent Events
• Chapter 13: Transmission
  • Transmissibility
  • Transmission Models
  • Transmission by the Meta Agent
  • Other Ways to Model Transmission
• Chapter 14: Modularity
  • Include Files and FRED_PATH
  • Modules
  • Defining a FRED Module
• Chapter 15: Snapshots and Restarts
  • Creating Snapshots
  • Fetching Snapshots
  • Restarts
• Chapter 16: Transition Guide for FRED Users
  • FRED_LIBRARY environmental variable
  • Random Number Stream
  • Admin Agents
  • Declaring Variables
  • Initialization
  • Start State
  • Factors
  • Order of Agent Transition Events
  • Synthetic Population
  • Adding Agents and Places
  • Default Model
  • Printing
  • Renamed Predicates
  • New Functions
  • Renamed Functions
  • Removed Functions

For information on compiling and executing FRED programs, please see the FRED Modeling Platform™ documentation. If you have questions about the company or are interested in speaking with our sales, recruiting, or other teams, please visit the Epistemix web site.