Modellus Documentation
Everything you need to build, simulate, and analyze mathematical models. Learn about each shape type, the expression language, data analysis tools, and more.
Editors
Modellus offers two ways to build a model: the free-form Board canvas and the document-style Notebook.
Board
Place shapes freely on a canvas and run live simulations.
Notebook
Combine narrative and live simulation blocks in a document.
Shapes
Every element on the Modellus board is a shape. Each shape type has unique capabilities.
To add a shape, click its button in the top toolbar and then click and drag on the board to draw it at the size you want. Press Esc or click the button again to cancel.
Expression
Write equations and define the mathematics of your model.
Table
Display computed values, enter data, select cells for regression.
Initial Values
Edit the starting values of model terms, per case.
Chart
Visualize data series, regression curves, and outliers.
Frequencies
Count and summarise the discrete values a term takes.
Body
Animated characters that move according to your equations.
Point
A positioned dot on the board, driven by expressions.
Line
Connect two points or draw directional segments.
Arc
Draw arcs and angles between directions.
Vector
Display arrows with magnitude and direction from equations.
Slider
Interactive control to adjust parameters in real time.
Gauge
Circular dial displaying a term value visually.
Value
Show a numeric value label for any term.
Media
Embed images and backgrounds on the board.
Text
Add rich text annotations and labels.
Ruler
Measure distances on the board canvas.
Protractor
Measure and display angles interactively.
Referential
Coordinate system for positioning child shapes.
Question
Create assessment questions within a model.
Mind Map
Bubbles, boxes, circles and connectors for organising ideas.
Components
Clock, compass, speedometer and other objects built from reusable blocks.
Building Blocks
Objects that are not one of the shapes above — a clock, a compass, a speedometer, a thermometer, a steering wheel — are composed from a closed set of approved building blocks, and a new one is a single JSON document. These pages are the construct: what the blocks are, the document a new object is written as, and every block with its properties.
Building Blocks
The layers, the registry, and how a drawing is made from them.
Object Definition
The document a new object is written as, field by field, with a worked example.
Block Reference
Every block with its properties, defaults and ranges, from the live registry.
Data Analysis
Modellus includes tools for statistical analysis of data collected in tables.
Regression
Fit linear or quadratic curves to your data points.
Outliers
Detect and visualize outlier data points in charts.
Community
Discover, publish, and manage scientific models, videos, data sets, and animated characters.
For AI Agents
Machine-readable reference for AI tools that generate or interpret Modellus models.