Ligral

Ligral is a textual simulation language as an alternative to Simulink. The goal of ligral is to describe simulation models with a set of statements instead of a graphic implementation. The syntax of ligral ensures equally powerful ability of model description. Meanwhile, ligral provides various solvers to solve the ode problems given by the interpreter.

How to Install

We now have released v0.2.2 which is available at GitHub. Alternatively, you may also want to clone the source to your workspace and build ligral manually.

git clone https://github.com/jry-zheng/ligral.git
cd ligral
dotnet build
./bin/Debug/netcoreapp3.1/ligral

For detailed installation guide see Quick Start。

Usage

The main function of ligral absolutely is run a simulation project. The project name, usually a .lig file name, should be the first positional parameter, like ligral path/file.lig. Besides, many parameters are supported:

The other commands that ligral supports include doc, trim, lin and exm, run ligral [command] --help to see more about the usage.

Dependency

If InnerPlotter is enabled and Scope or PhaseDiagram is used in your project, you need python 3 to let them work. Packages numpy、matplotlib、pandas are also required.

Examples

Following is a mass-spring-damper system implemented by ligral.

# Define a route named MassSpringDamper
route MassSpringDamper(m, k, d, x0, v0; F; x, v)
    F-k*x-d*v -> Gain{value:1/m} -> Integrator{initial:v0} -> v;
    v -> Integrator{initial:x0} -> x;
end

# Define a step signal
Step[F]{start:3, level:5};

# Instantiate a MassSpringDamper object
MassSpringDamper[sys]{m:0.1, k:10, d:0.3, x0:1, v0: 0};

# Link models
F -> sys;
sys:x[position] -> Scope;
(sys:x, sys:v[velocity]) -> PhaseDiagram;

# Configure the solver
conf step_size = 0.001;
conf stop_time = 10;

# Redirect the output folder
conf output_folder = 'out';

More examples see examples.

Syntax

See detailed syntax in User Guide, which are written in Chinese currently. If you are interested in ligral but cannot read Chinese, please contact me via zhengjry@outlook.com. Followings are completed:

• Terms
• Configure statements
• How to declare a constant?
• How to declare a node?
• How to link nodes?
• Matrices in ligral
• What is route?
• Reference packages
• What is signature?

Development

We are working hard to write Development Guide. Now the followings are available with Chinese version.

• Syntax design
• Interpreter Implementation
• ...

If you found a bug please submit an issue.

Development plan:

• Add unit test;
• Add if-else, for, while statements and functions syntax for pre- and post-simulation process;
• Unify the data signal to be a matrix, which means a scalar will be regarded as a 1 by 1 matrix;
• Fix bugs
• ...