cicwave 0.5.0

Advanced waveform viewer with PyQtGraph backend

cicwave

Waveform viewer with PyQtGraph backend for high-performance visualization of simulation data.

cicwave is a standalone package extracted from cicsim, focused on providing the best possible waveform viewing experience with PyQtGraph and Qt6.

Background

I made my first waveform viewer (https://github.com/wulffern/NextGenLab.Chart) back in 2001 during a summer internship. NextGenLab.Chart evolved into https://github.com/wulffern/SystemDotNet.Report during my Ph.D. In I always had in my plan to port SdnReport to Mac and Linux, but I never really did (no coding time).

In December 2023 I needed a waveform viewer for cicsim (read ngspice raw files), so I wrote one by hand. It was pretty basic.

Enter March 2026, and the advent of agentic coding. It was finally possible to revive SdnReport in the form of a Qt port to cicwave. Initially it lived inside cicsim, however, in May 2026 it became clear that cicwave deserved it's own repo. As such, you're here.

Features

• High-performance rendering with PyQtGraph and GPU acceleration
• Multiple file format support:
  • ngspice .raw files
  • CSV, TSV, Excel spreadsheets
  • Parquet, HDF5, Feather for big data
  • VCD digital waveforms
  • LitePoint .iqvsa IQ capture files
• Multi-dimensional data pivoting with YAML specifications
• Digital waveform support with separate analog/digital panes
• Session save/restore with .cicwave.yaml files
• Export capabilities to PDF, PNG, SVG formats
• Engineering unit formatting and auto-detection
• GPU-accelerated plotting for smooth interaction with large datasets

Installation

pip install cicwave

For development installation:

git clone https://github.com/wulffern/cicwave.git
cd cicwave
pip install -e .

Usage

Basic Usage

Open waveform files directly:

# Single file
cicwave data.raw

# Multiple files  
cicwave sim1.csv sim2.csv results.xlsx

# Glob patterns (useful on PowerShell)
cicwave --glob "results/*.csv" --glob "**/*.raw"

Advanced Features

Multi-dimensional data reshaping:

cicwave --pivot analysis.yaml dataset.csv

Session management:

# Save your current plot configuration in the GUI (File → Save Session)
cicwave --session my_analysis.cicwave.yaml

# Export plots without opening GUI
cicwave --session config.yaml --export results.pdf

Data exploration:

# Preview pivot dimensions before plotting
cicwave --pivot spec.yaml --pivot-info data.csv

File Format Support

Format	Extension	Description
ngspice	.raw	Binary simulation results
CSV/TSV	.csv, .tsv	Comma/tab separated values
Excel	.xlsx	Spreadsheet format
Parquet	.parquet	Columnar storage (requires pip install pyarrow)
HDF5	.h5	Hierarchical data (requires pip install tables)
VCD	.vcd	Digital simulation waveforms
LitePoint	.iqvsa	IQ capture data

Environment Variables

• CICWAVE_X - Default X-axis column name

GUI Features

Waveform Interaction

• Mouse wheel: Zoom in/out
• Middle click + drag: Pan
• Right click: Context menu with analysis tools
• Ctrl+A: Auto-fit all waveforms
• Ctrl+Mouse wheel: Zoom X-axis only

Analysis Tools

• Cursors: Measure time/voltage differences
• Math expressions: Create derived signals
• Digital analysis: View bus values and timing
• Export data: Save currently visible waveforms

Session Management

• File → Save Session: Save current plot configuration
• File → Load Session: Restore previous analysis
• Sessions store: visible signals, zoom levels, cursor positions, analysis setup

Pivot Specifications

For multi-dimensional datasets, use YAML pivot specs to reshape data before visualization:

# analysis.yaml
index: time          # X-axis (rows)
columns: [corner, temperature]  # Create separate traces for each combination  
values: ["v(out)", "v(in)"]     # Y-axis signals to plot
conditions:          # Filter data
  frequency: 1e9
  process: tt

cicwave --pivot analysis.yaml monte_carlo_results.csv

Migrating from cicsim

If you previously used cicsim wave or the standalone cicwave from cicsim:

1. Install standalone cicwave: pip install cicwave
2. Update workflows: Replace cicsim wave --backend pg with just cicwave
3. Session files: Existing .cicwave.yaml files are fully compatible
4. Tkinter users: cicsim wave --backend tk still works in cicsim for lightweight usage

Development

Running Tests

# Run all unit tests
python -m unittest discover -s tests/unittests/ -p 'test_*.py' -v

# Test specific functionality
python -m unittest tests.unittests.test_wavefiles_lazy -v

Project Structure

cicwave/
├── src/cicwave/
│   ├── cli.py          # Command-line interface
│   ├── wave_pg.py      # Main PyQtGraph viewer
│   ├── wavefiles.py    # File I/O and data loading
│   ├── ngraw.py        # ngspice binary parser  
│   ├── pivot.py        # Data reshaping
│   ├── theme.py        # Color themes
│   └── command.py      # Logging utilities
├── tests/unittests/    # Unit test suite
└── scripts/            # Windows shortcut generator

License

MIT License - see LICENSE file for details.

Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Ensure all tests pass
5. Submit a pull request

Related Projects

• cicsim - Simulation orchestration and lightweight tkinter viewer
• cicpy - Analog IC design transpiler
• PyQtGraph - High-performance plotting library