This guide covers known issues, common problems, and their solutions. It also includes information about future updates and the development roadmap.
'python' is not recognized as an internal or external command
Solution:
- Verify Python installation: Open Command Prompt/Terminal.
- Try
python --versionorpython3 --version. - If not found, install Python from python.org.
- Important: During installation, check "Add Python to PATH".
- Restart terminal after installation.
ERROR: Virtual environment not found
Please run setup.bat first
(or setup.sh on macOS/Linux)
Solution: The bin/ launchers (run.bat, run.sh, run_streamlit.bat, run_streamlit.sh, run_tests.bat, run_tests.sh) require a project virtual environment. From the project root, run:
- Windows:
setup.bat - macOS/Linux:
chmod +x setup.shthen./setup.sh
Then run the desired launcher again.
Permission denied: ./install.sh
Solution:
chmod +x install.sh
chmod +x setup.sh
chmod +x bin/run.sh
chmod +x bin/run_streamlit.sh
./install.shcannot be loaded because running scripts is disabled on this system
Solution:
- Open PowerShell as Administrator.
- Run:
Set-ExecutionPolicy RemoteSigned. - Confirm with 'Y'.
- Retry activation:
.venv\Scripts\Activate.ps1.
ModuleNotFoundError: No module named 'numpy'
Solution:
- Ensure virtual environment is activated.
- You should see
(.venv)in your terminal prompt. - Windows:
.venv\Scripts\activate. - macOS/Linux:
source .venv/bin/activate.
- You should see
- Reinstall dependencies:
pip install -r requirements.txt
- Verify installation:
pip list | grep numpy
Solution:
- Check file exists in specified location.
- Use absolute path if relative path fails.
- Check file permissions (read access required).
- Verify file extension (.csv, .xlsx, .txt).
Solution:
- Open file in text editor to verify content.
- Check delimiter (comma, semicolon, tab).
- Ensure first row contains column headers.
- Remove any blank lines at beginning of file.
Solution:
- Ensure
openpyxlis installed:pip install openpyxl. - Check file isn't password-protected.
- Verify file isn't corrupted (try opening in Excel).
- Save as .xlsx format (newer format more reliable).
Solution:
- Verify naming: uncertainty for column
xmust be namedux. - Use lowercase
uprefix. - Check for extra spaces in column names.
- Ensure uncertainty columns contain numeric values.
RuntimeError: Optimal parameters not found
Causes:
- Not enough data points (need at least 5-10).
- Data doesn't match equation type.
- Bad initial parameter guess.
- Equation too complex for data.
Solutions:
-
Check data quality:
- Plot data first (use "Watch Data").
- Look for obvious outliers.
- Ensure sufficient data points.
-
Try different equation:
- Start with simpler equations (linear, quadratic).
- Use Checker mode to test multiple equations.
-
Provide better initial guess:
- For custom formulas, estimate parameters manually.
- Look at data range to guess amplitudes.
-
Simplify the model:
- Reduce number of parameters.
- Remove unnecessary complexity.
Causes:
- Wrong equation type for data.
- Noisy data.
- Outliers present.
- Insufficient data points.
Solutions:
-
Try different equations:
- Use Checker or Total Fitting mode.
- Compare R² values across equations.
-
Clean data:
- Use Loop mode to iteratively remove outliers.
- Filter data before fitting.
-
Check for systematic issues:
- Is there a trend the equation doesn't capture?
- Are there periodic components?
- Is data actually stochastic?
a = 2.5 ± 10.3 (uncertainty > parameter value!)
Causes:
- Poorly conditioned problem.
- Parameters are correlated.
- Not enough data to constrain parameters.
- Wrong equation type.
Solutions:
- Collect more data: More points reduce uncertainties.
- Extend data range: Cover wider range of X values.
- Reduce parameters: Simpler model may be better.
- Fix some parameters: If you know certain values, fix them.
Solution:
- Check output directory exists and is writable.
- Verify matplotlib is installed:
pip install matplotlib. - Check logs for error messages:
regressionlab.log. - Try recreating virtual environment.
Solution:
- Increase DPI in
.env:DPI=300 # For high-quality plots
- Adjust figure size:
PLOT_FIGSIZE_WIDTH=12 PLOT_FIGSIZE_HEIGHT=6
- Modify font sizes in
.env.
Solution:
- Verify uncertainty columns exist and are named correctly.
- Check uncertainties are non-zero.
- Ensure uncertainties are numeric (not strings).
- Try with test data to isolate issue.
Solution:
- Check if dialog is behind main window (Alt+Tab).
- Look in taskbar for new windows.
- Disable "Always on top" if using other applications.
- Restart application.
Solution:
Edit .env file:
UI_FONT_SIZE=16 # Increase for larger text
UI_BUTTON_WIDTH=15 # Increase for wider buttonsRestart application.
Solution: Reset to default theme:
- Copy
.env.exampleto.env - Or manually set high-contrast colors:
UI_BACKGROUND="white" UI_FOREGROUND="black"
- Restart application.
Solution:
- Check file size (< 200 MB for online version).
- Verify file format (CSV, XLSX, TXT).
- Clear browser cache and retry.
- Try different browser.
- Check browser console for JavaScript errors (F12).
Solution:
- This is expected behavior - Streamlit doesn't persist results.
- Download plots before refreshing.
- Use Tkinter version if persistence needed.
Solution:
- Close other tabs to free memory.
- Use local version for better performance.
- Reduce dataset size.
- Avoid Total Fitting mode for large datasets.
An Android installer has been attempted using Termux (terminal emulator) and Termux:X11 for the graphical interface. This approach has not been successful.
Main obstacle: Installing dependencies reliably, especially scipy. The standard pip install -r requirements.txt fails in Termux due to compilation and compatibility issues with the ARM architecture and Termux's environment.
Alternative that works (manual only): Pydroid 3 allows running the application by installing each library manually with the appropriate options. However, Pydroid 3 does not support automated installation scripts, so a one-click or scripted installer is not feasible.
Summary:
- Termux + Termux:X11: Library installation (scipy in particular) fails; no working solution found.
- Pydroid 3: Works with manual per-library installation, but cannot be automated.
Android support remains a long-term goal; contributions or solutions to the dependency installation problem are welcome. If you want to see the best point I reached, check the
scripts/install_termux.shandscripts/setup_termux.shfiles.
Edit .env:
LOG_LEVEL=DEBUG
LOG_CONSOLE=trueView logs:
# Real-time log viewing
tail -f regressionlab.log
# Windows
type regressionlab.log# Verify Python version
python --version # Should be 3.12+
# Check virtual environment is activated
which python # Should point to .venv
# List installed packages
pip list
# Check specific package version
pip show numpy- Test with sample data: Use files in
input/folder. - Test different modes: Does issue occur in all modes?
- Test both interfaces: Try Tkinter AND Streamlit.
- Minimal example: Create simplest case that reproduces issue.
If you can't solve the issue, please report it on GitHub with:
- Version: Check version in main menu or
config(e.g.config/constants.py). - Operating System: Windows, macOS, or Linux (with version).
- Python Version: Output of
python --version. - Steps to Reproduce: Exact steps to trigger the issue.
- Expected Behavior: What should happen.
- Actual Behavior: What actually happens.
- Error Messages: Full error message and traceback.
- Logs: Relevant portions of
regressionlab.log. - Screenshots: If UI-related.
- Sample Data: If possible, include data file that triggers issue.
Under Consideration:
- Time-series analysis tools.
- Machine learning models (SVM, Random Forest, Neural Networks).
- Bayesian regression and uncertainty quantification.
- Automated model selection and comparison tools.
- Check existing issues: Avoid duplicates.
- Open GitHub issue: Use "Feature Request" template.
- Describe use case: Why is this feature needed?
- Provide examples: Show what you want to achieve.
- Be patient: We're a one person team!
- Use compiled Python: Try PyPy for pure Python code.
- Reduce plot resolution: Lower DPI for faster rendering.
- Disable logging: Set
LOG_LEVEL=WARNINGin production. - Use local version: Avoid network latency.
- Close result windows: Free memory between fits.
- Provide uncertainties: Weighted fitting is more accurate.
- Use appropriate equation: Don't over-complicate.
- Collect more data: More points = better parameter estimates.
- Extend data range: Cover full range of interest.
-
Documentation: Start here!
-
Examples: Check
input/folder for sample datasets. -
GitHub:
- Issues: Report bugs.
- Discussions: Ask questions.
-
Community:
- Share your analyses.
- Contribute code.
- Improve documentation.
- Email: alejandro.mata.ali@gmail.com.
- GitHub: Open an issue for bugs/features.
Document last updated: February 2026. If you solved a problem not listed here, please contribute by opening a pull request!