Scientific Schematics - Nano Banana Pro

Generate any scientific diagram by describing it in natural language.

Nano Banana Pro creates publication-quality diagrams automatically - no coding, no templates, no manual drawing required.

Quick Start

Generate Any Diagram

# Set your OpenRouter API key
export OPENROUTER_API_KEY='your_api_key_here'

# Generate any scientific diagram
python scripts/generate_schematic.py "CONSORT participant flow diagram" -o figures/consort.png

# Neural network architecture
python scripts/generate_schematic.py "Transformer encoder-decoder architecture" -o figures/transformer.png

# Biological pathway
python scripts/generate_schematic.py "MAPK signaling pathway" -o figures/pathway.png

What You Get

Up to two iterations (v1, v2) with progressive refinement
Automatic quality review after each iteration
Detailed review log with scores and critiques (JSON format)
Publication-ready images following scientific standards

Features

Iterative Refinement Process

Generation 1: Create initial diagram from your description
Review 1: AI evaluates clarity, labels, accuracy, accessibility
Generation 2: Improve based on critique
Review 2: Second evaluation with specific feedback
Generation 3: Final polished version

Automatic Quality Standards

All diagrams automatically follow:

Clean white/light background
High contrast for readability
Clear labels (minimum 10pt font)
Professional typography
Colorblind-friendly colors
Proper spacing between elements
Scale bars, legends, axes where appropriate

Installation

For AI Generation

# Get OpenRouter API key
# Visit: https://openrouter.ai/keys

# Set environment variable
export OPENROUTER_API_KEY='sk-or-v1-...'

# Or add to .env file
echo "OPENROUTER_API_KEY=sk-or-v1-..." >> .env

# Install Python dependencies (if not already installed)
pip install requests

Usage Examples

Example 1: CONSORT Flowchart

python scripts/generate_schematic.py \
  "CONSORT participant flow diagram for RCT. \
   Assessed for eligibility (n=500). \
   Excluded (n=150): age<18 (n=80), declined (n=50), other (n=20). \
   Randomized (n=350) into Treatment (n=175) and Control (n=175). \
   Lost to follow-up: 15 and 10 respectively. \
   Final analysis: 160 and 165." \
  -o figures/consort.png

Output:

figures/consort_v1.png - Initial generation
figures/consort_v2.png - After first review
figures/consort_v3.png - Final version
figures/consort.png - Copy of final version
figures/consort_review_log.json - Detailed review log

Example 2: Neural Network Architecture

python scripts/generate_schematic.py \
  "Transformer architecture with encoder on left (input embedding, \
   positional encoding, multi-head attention, feed-forward) and \
   decoder on right (masked attention, cross-attention, feed-forward). \
   Show cross-attention connection from encoder to decoder." \
  -o figures/transformer.png \
  --iterations 2

Example 3: Biological Pathway

python scripts/generate_schematic.py \
  "MAPK signaling pathway: EGFR receptor → RAS → RAF → MEK → ERK → nucleus. \
   Label each step with phosphorylation. Use different colors for each kinase." \
  -o figures/mapk.png

Example 4: System Architecture

python scripts/generate_schematic.py \
  "IoT system block diagram: sensors (bottom) → microcontroller → \
   WiFi module and display (middle) → cloud server → mobile app (top). \
   Label all connections with protocols." \
  -o figures/iot_system.png

Command-Line Options

python scripts/generate_schematic.py [OPTIONS] "description" -o output.png

Options:
  --iterations N          Number of AI refinement iterations (default: 2, max: 2)
  --api-key KEY          OpenRouter API key (or use env var)
  -v, --verbose          Verbose output
  -h, --help             Show help message

Python API

from scripts.generate_schematic_ai import ScientificSchematicGenerator

# Initialize
generator = ScientificSchematicGenerator(
    api_key="your_key",
    verbose=True
)

# Generate with iterative refinement
results = generator.generate_iterative(
    user_prompt="CONSORT flowchart",
    output_path="figures/consort.png",
    iterations=2
)

# Access results
print(f"Final score: {results['final_score']}/10")
print(f"Final image: {results['final_image']}")

# Review iterations
for iteration in results['iterations']:
    print(f"Iteration {iteration['iteration']}: {iteration['score']}/10")
    print(f"Critique: {iteration['critique']}")

Prompt Engineering Tips

Be Specific About Layout

✓ "Flowchart with vertical flow, top to bottom"
✓ "Architecture diagram with encoder on left, decoder on right"
✗ "Make a diagram" (too vague)

Include Quantitative Details

✓ "Neural network: input (784), hidden (128), output (10)"
✓ "Flowchart: n=500 screened, n=150 excluded, n=350 randomized"
✗ "Some numbers" (not specific)

Specify Visual Style

✓ "Minimalist block diagram with clean lines"
✓ "Detailed biological pathway with protein structures"
✓ "Technical schematic with engineering notation"

Request Specific Labels

✓ "Label all arrows with activation/inhibition"
✓ "Include layer dimensions in each box"
✓ "Show time progression with timestamps"

Mention Color Requirements

✓ "Use colorblind-friendly colors"
✓ "Grayscale-compatible design"
✓ "Color-code by function: blue=input, green=processing, red=output"

Review Log Format

Each generation produces a JSON review log:

{
  "user_prompt": "CONSORT participant flow diagram...",
  "iterations": [
    {
      "iteration": 1,
      "image_path": "figures/consort_v1.png",
      "prompt": "Full generation prompt...",
      "critique": "Score: 7/10. Issues: font too small...",
      "score": 7.0,
      "success": true
    },
    {
      "iteration": 2,
      "image_path": "figures/consort_v2.png",
      "score": 8.5,
      "critique": "Much improved. Remaining issues..."
    },
    {
      "iteration": 3,
      "image_path": "figures/consort_v3.png",
      "score": 9.5,
      "critique": "Excellent. Publication ready."
    }
  ],
  "final_image": "figures/consort_v3.png",
  "final_score": 9.5,
  "success": true
}

Why Use Nano Banana Pro

Simply describe what you want - Nano Banana Pro creates it:

✓ Fast: Results in minutes
✓ Easy: Natural language descriptions (no coding)
✓ Quality: Automatic review and refinement
✓ Universal: Works for all diagram types
✓ Publication-ready: High-quality output immediately

Just describe your diagram, and it's generated automatically.

Troubleshooting

API Key Issues

# Check if key is set
echo $OPENROUTER_API_KEY

# Set temporarily
export OPENROUTER_API_KEY='your_key'

# Set permanently (add to ~/.bashrc or ~/.zshrc)
echo 'export OPENROUTER_API_KEY="your_key"' >> ~/.bashrc

Import Errors

# Install requests library
pip install requests

# Or use the package manager
pip install -r requirements.txt

Generation Fails

# Use verbose mode to see detailed errors
python scripts/generate_schematic.py "diagram" -o out.png -v

# Check API status
curl https://openrouter.ai/api/v1/models

Low Quality Scores

If iterations consistently score below 7/10:

Make your prompt more specific
Include more details about layout and labels
Specify visual requirements explicitly
Increase iterations: --iterations 2

Testing

Run verification tests:

python test_ai_generation.py

This tests:

File structure
Module imports
Class initialization
Error handling
Prompt engineering
Wrapper script

Cost Considerations

OpenRouter pricing for models used:

Nano Banana Pro: ~$2/M input tokens, ~$12/M output tokens

Typical costs per diagram:

Simple diagram (1 iteration): ~$0.05-0.15
Complex diagram (2 iterations): ~$0.10-0.30

Examples Gallery

See the full SKILL.md for extensive examples including:

CONSORT flowcharts
Neural network architectures (Transformers, CNNs, RNNs)
Biological pathways
Circuit diagrams
System architectures
Block diagrams

Support

For issues or questions:

Check SKILL.md for detailed documentation
Run test_ai_generation.py to verify setup
Use verbose mode (-v) to see detailed errors
Review the review_log.json for quality feedback

License

Part of the scientific-writer package. See main repository for license information.

/scientific-schematics

README.md