Download, install, configure and test SLiCAP
Requirements
You need to have python 3.12+ installed
Under MSWindows it is strongly advised to install Python under Anaconda
Install SLiCAP
If you work with Anaconca open the Anaconda Prompt
If you have Python installed under Windows, open a terminal by running the command cmd
If you have Python installed under Linux or mac Open a terminal
Enter:
pip install slicap
Upgrade SLiCAP
If you have SLiCAP installed and you want to upgrade to the latest version:
If you work with Anaconca open the Anaconda Prompt
If you have Python installed under Windows, open a terminal by running the command cmd
If you have Python installed under Linux or mac Open a terminal
Enter:
pip install slicap --upgrade
Other packages
SLiCAP has symbol libraries for creating circuit diagrams with:
KiCAD. This is the preferred package fo working with SLiCAP
For these packages, SLiCAP also has build in netlist generation. SLiCAP uses python scripts for scaling of KiCAD images from page format to drawing format. For detaied information see Schematic capture.
SLiCAP also interacts with NGspice for performing more elaborate numeric simulations.
Completing and testing the installation
After installing or updating SLiCAP, you can use it as any other Python package. On its first import, however, SLiCAP searches for installed software for schematic capture or SPICE simulation, and store this information in a SLiCAP.ini file in the user home directory: ~/SLiCAP.ini. You can edit this file manually or delete it. SLiCAP generates an updated version on the next run.
First import under MSWindows
>>> import SLiCAP as sl
Updating main configuration file; this may take a while.
Do you have NGspice installed? [y/n] >>> y
Searching installed software, this will time-out after 120 seconds!
KiCad command set as: C:\Program Files\KiCad\kicad-cli.exe
LTSpice command set as: C:\Program Files\LTC\LTspiceXVII\XVIIx64.exe
gnetlist command set as: C:\Program Files (x86)\gEDA\gnetlist.exe
NGspice command set as: C:\Users\<USER>\ngspice\Spice64\ngspice.exe
SLiCAP found all installed apps!
SLiCAP Version matches with the latest release of SLiCAP on github.
Generating project configuration file: SLiCAP.ini.
First import under Linux or MacOS
>>> import SLiCAP as sl
Generating main configuration file: ~/SLiCAP.ini.
/usr/bin/kicad-cli
/usr/bin/lepton-cli
/usr/bin/ngspice
SLiCAP Version matches with the latest release of SLiCAP on github.
Generating project configuration file: SLiCAP.ini.
Main configuration
Updating of the main configuration file ~/SLiCAP.ini is recommended if:
One or more apps listed above are installed or removed
During installation under MS-Windows, searching to the apps listed above timed out
Below an example of the command section for user “USER” under MS-Windows with default installation of all apps (lepton-eda is not available under MS-Windows). The main configuration file is located at: C:\Users\USER\SLiCAP.ini
[commands]
lepton-eda =
kicad = C:\Program Files\KiCad\9.0\bin\kicad-cli.exe
ltspice = C:\Program Files\LTC\LTspiceXVII\XVIIx64.exe
geda = C:\Program Files (x86)\gEDA\gEDA\bin\gnetlist.exe
ngspice = C:\Users\USER\ngspice\Spice64\bin\ngspice.exe
Below an example of the command section for user “USER” under Linux or MacOS with default installation of LTspice under wine. The main configuration file is located at: ~/SLiCAP.ini:
[commands]
ltspice = /home/USER/.wine/drive_c/Program Files/ADI/LTspice/LTspice.exe
kicad = kicad-cli
geda = lepton-netlist
lepton-eda = lepton-cli
ngspice = ngspice
Important
SLiCAP works well without having additional packages installed. The only function that searches for installed apps is makeCircuit.
Project configuration
SLiCAP projects should be placed in separate project folders. In this folder you save the Python script(s) or Jupyter Notebook(s) for your project. On the first run of your Python project script:
Creates the directory structure in the project folder
Copies some library files
Creates a project configuration file SLiCAP.ini in the project directory.
This configuration file contains default math settings, color settings, etc. You can edit or delete this file. After deletion it will be recreated at the next project run.
The python script below (user=USER, python environment=USER, os=LINUX) generates/updates the configuration files, displays their contents and opens the HTML documentation in the default browser:
# Import the SLiCAP modules in a separate namespace (preferred)
# Create (but don't override) the main configuration file ``SLiCAP.ini`` in the ~/ folder
import SLiCAP as sl
# Create the project folder structure
# Start an HTML report
# Compiles the libraries
# Create (but don't override) the project configuration file ``SLiCAP.ini`` in the project folder
sl.initProject('SLiCAP test')
# Display the configuration settings:
sl.ini.dump()
# Open de HTML documentation in the browser:
sl.Help()
Generating project configuration file: SLiCAP.ini.
Compiling library: SLiCAP.lib.
Compiling library: SLiCAPmodels.lib.
ini.install_version = 3.5.7
ini.latest_version = 3.5.7
ini.install_path = /home/USER/USER/lib/python3.12/site-packages/
ini.home_path = /home/USER/
ini.main_lib_path = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/lib/
ini.doc_path = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/docs/html/
ini.ltspice = /home/USER/.wine/drive_c/Program Files/ADI/LTspice/LTspice.exe
ini.gnetlist = lepton-netlist
ini.kicad = kicad-cli
ini.ngspice = ngspice
ini.lepton_eda = lepton-cli
ini.ltspice_syms = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/LTspice/
ini.gnetlist_syms = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/gSchem/
ini.kicad_syms = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/kicad/SLiCAP.kicad_sym
ini.lepton_eda_syms = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/lepton-eda/
ini.latex_files = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/tex/
ini.sphinx_files = /home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/sphinx/
ini.html_path = html/
ini.cir_path = cir/
ini.img_path = img/
ini.csv_path = csv/
ini.txt_path = txt/
ini.tex_path = tex/
ini.user_lib_path = lib/
ini.mathml_path = mathml/
ini.sphinx_path = sphinx/
ini.html_prefix =
ini.html_index = index.html
ini.html_page = index.html
ini.html_pages = ['']
ini.html_labels = <Section: labels>
ini.disp = 4
ini.hz = True
ini.notebook = False
ini.scalefactors = False
ini.eng_notation = True
ini.last_updated = 2025-05-14 15:14:01
ini.project_title = SLiCAP test
ini.created = 2025-05-14 15:14:00
ini.author = USER
ini.laplace = s
ini.frequency = f
ini.numer = ME
ini.denom = ME
ini.lambdify = numpy
ini.step_function = True
ini.factor = True
ini.max_rec_subst = 15
ini.reduce_matrix = True
ini.reduce_circuit = True
ini.gain_colors = {'asymptotic': 'r', 'gain': 'b', 'loopgain': 'k', 'servo': 'm', 'direct': 'g', 'vi': 'c'}
ini.plot_fontsize = 12
ini.axis_height = 5
ini.axis_width = 7
ini.line_width = 2
ini.marker_size = 7
ini.line_type = -
ini.legend_loc = best
ini.default_colors = ['r', 'b', 'g', 'c', 'm', 'y', 'k']
ini.default_markers = ['']
ini.plot_fontsize = 12
ini.plot_file_type = svg
ini.svg_margin = 1
Change settings
It is strongly advised not to change any settings in the project SLiCAP.ini file. The preferred way of changing settings is to do it in the python scripts. Some examples are given below.
>>> import SLiCAP as sl
>>> sl.ini.disp = 3 # set the number of significant digits in reports and listings to 3
>>> sl.ini.hz = False # set the default frequency units to *rad/s*
>>> sl.ini.max_rec_subst = 20 # set the maximum number of recursive substitutions in expressions to 20
>>> sl.ini.reduce_circuit = False # Do NOT eliminate unused independent voltage sources from the circuit
# If True, the size of MNA matrices comprising independent voltage sources will be reduced
# by eliminating these sources if they are not used as signal source or detector
>>> sl.ini.reduce_matrix = False # Do NOT eliminate variables and reduce the matrix size before calculating the determinant
# If True, the size of MNA matrices comprising Laplace expressions will be reduced through
# elimination of variables, until all matrix enties are either zero or Laplace polynomials
# of the first order or higher
>>> sl.ini.numer = "BS" # Use Bareiss division-free determinant calculation method for the numerator
# Default is ``ME``: recursive expansion of minors
>>> sl.ini.denom = "BS" # Use Bareiss division-free determinant calculation method for the denominator
# Default is ``ME``: recursive expansion of minors
Find SLiCAP schematic symbols libraries
From version 3.3.0, SLiCAP symbol libraries are stored in the package directory. You need these locations for configuring your schematic capture program:
>>> import SLiCAP as sl
>>> sl.ini.kicad_syms
'/home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/kicad/SLiCAP.kicad_sym'
>>> sl.ini.ltspice_syms
'/home/USER/USER/lib/python3.12/site-packages/SLiCAP/files/LTspice/'
Run SLiCAP from within Jupyter notebooks
Jupyter Notebooks can also run SLiCAP scripts. For proper rendering of all HTML output to your notebook set the keyword argument notebook=True
with initProject().
# Import the SLiCAP modules in a separate namespace (preferred)
# Create (but don't override) the main configuration file ``SLiCAP.ini`` in the ~/ folder
import SLiCAP as sl
# Create the project folder structure
# Compiles the libraries
# Create (but don't override) the project configuration file ``SLiCAP.ini`` in the project folder
sl.initProject('SLiCAP test', notebook=True)