STLRom

STLRom is a C++ library with python bindings for Robust Online Monitoring of Signal Temporal Logic. It computes interval robustness loosely as defined in 'Robust online monitoring of signal temporal logic' by Deshmuk et al, although the algorithm is not exactly the one described in this paper.

Install

Requirements

Building and installing STLRom has been tested on Linux (Ubuntu) and Mac OS. STLRom depends on "recent" versions of Flex and Bison. To install them on Linux, use apt. On Mac OS, Homebrew is required:

brew install bison flex 

If you don't like Homebrew, it is probably not required, provided you like messing with CMakeList.txt files. As long as the thing can find the required Bison and Flex libraries, that should work.

Install from pypi

In an environment with pip, first make sure that python-dev or equivalent is installed, e.g., in Ubuntu 24.04:

sudo apt install python-dev-is-python3

To build the library, bison and flex are also required, as mentioned above. Then build and install with pip:

pip install stlrom

Install from source

Requirements: same as above (bison,flex and python-dev).

Python

Using pip

From the stlrom folder, install with

pip install -e .

Using uv (Recommended)

A python interface for stlrom is implemented with pybind11. To build and install it in a local virtual environment we recommend using uv. To create a virtual environment, build and install stlrom, run:

uv venv
source .venv/bin/activate
uv pip install -e .

Note this requires compiling the C++ library, so cmake and a C++ compiler must be available.

It is also possible to install the Python interface by simply running the following command in the project's root directory:

uv sync

then you can activate the virtual environment by running

source .venv/bin/activate

and then using Python normally inside the virtual enviornment.

Testing the python bindings

In the build folder, execute

make test-python

This will run the unit tests python programs from the test folder. This assumes having run cmake, having built the Python library, and having activated the uv virtual environment.

Building the C++ library only

STLRom is primarily a C++ library. It comes with a standard cmake configuration file. Assuming cmake and a C++ development environment are installed, a library called stlromlib can be built with

mkdir build; cd build
cmake ..
make

Testing the C++ Library

After running cmake in the build folder and building the C++ library using make, you can run:

make test-cpp

to run C++ test files in the test folder.

Note: you can also execute make test to run both C++ and Python test units.

Usage

Tutorial Notebook

The following notebooks are hopefully good resources to get started.

• test/tutorial_notebook1.ipynb is formated as a quick tutorial for stlrom.
• test/tutorial_notebook2.ipynb is longer and has plots.

Of course, at least ipykernel is required for the notebooks execution.

A Complete Example

import stlrom


# define a "driver", which can parse and store a context of STL formulas, as well as data
stl_driver =stlrom.STLDriver()

s="""
signal x, y    # signal names
mux := x[t]>0  # simple predicate 

param a=1, b=2, p = -3   
muy := a*y[t] + b > p   # operation and parameter in predicate

phi1 := alw_[0, 5] mux               # always (G works too) 
phi2 := ev_[3, 4] (mux) or phi1      # eventually (or F)
phi_until := phi1 until_[0, 1] phi2  # until 
"""

# parse the formulas
stl_driver.parse_string(s)  # or write the above in spec.stl, and use parse_file('spec.stl')

# add data as timed samples
stl_driver.add_sample([0,  2 , 1 ])  # must be of the format [t, x_val, y_val]
stl_driver.add_sample([0.5, -3, 2])  # i.e., contain signal value with same order as declared
stl_driver.add_sample([2.1, 10, 20])

print(stl_driver)
print('Robustness of phi1 at time 0.: ', phi1.get_rob())
print('Robustness of phi1 from time 1.: ', phi1.get_rob(1.))

Test folder

In you don't mind the mess, the test folder contains several examples and test programs and scripts which may be useful.