Circos Plot Generator

Generate Circos configuration files for circular genomics data visualization. Supports genomic variations (SNPs, CNVs, structural variants), cell-cell communication networks, and custom track configurations for publication-ready circular plots.

Generate configuration files for Circos circular visualization plots, enabling genomics data visualization including genomic variations, chromosome ideograms, cell-cell communication networks, and custom track annotations. Simplifies the complex Circos configuration process for researchers without Perl expertise.

Key Capabilities:

• Genomic Variation Visualization: Create plots for SNPs, CNVs, structural variants (translocations, inversions)
• Cell-Cell Communication Networks: Visualize intercellular interactions and signaling pathways
• Chromosome Ideograms: Display chromosome structure with bands and annotations
• Multiple Track Types: Support histograms, scatter plots, links, heatmaps, and text tracks
• Publication-Ready Output: Generate configurations for high-quality PNG/SVG figures

---

When to Use

✅ Use this skill when:

• Visualizing genomic variations across chromosomes (SNPs, CNVs, SVs) for publication
• Creating circular genome maps showing multiple data types simultaneously
• Plotting cell-cell communication networks from single-cell RNA-seq data
• Displaying synteny or chromosomal rearrangements between genomes
• Creating circos plots for grant proposals, presentations, or papers
• Generating custom track visualizations for genomic features
• Comparing structural variants across multiple samples or conditions

❌ Do NOT use when:

• Needing interactive genome browsers (e.g., IGV, UCSC) → Use genome browser tools
• Creating linear genome plots → Use cnv-caller-plotter or gene-structure-mapper
• Analyzing time-series or trajectory data → Use trajectory analysis tools
• Working with protein structures → Use PyMOL or ChimeraX
• Requiring real-time data visualization → Use web-based dashboards
• Making simple bar charts or line plots → Use matplotlib, ggplot2, or Excel

Related Skills:

• 上游 (Upstream): cnv-caller-plotter, crispr-screen-analyzer, bio-ontology-mapper
• 下游 (Downstream): dpi-upscaler-checker, journal-cover-prompter, figure-legend-gen

---

Integration with Other Skills

Upstream Skills:

• cnv-caller-plotter: Generate CNV calls for visualization in Circos
• crispr-screen-analyzer: Prepare hit data for genomic context visualization
• bio-ontology-mapper: Map features to genomic coordinates for track display

Downstream Skills:

• dpi-upscaler-checker: Verify output resolution meets publication requirements
• journal-cover-prompter: Generate AI prompts for journal covers using Circos plots
• figure-legend-gen: Create figure legends for complex Circos visualizations

Complete Workflow:

text

WGS Data → cnv-caller-plotter → circos-plot-generator → dpi-upscaler-checker → Publication Figure

---

Core Capabilities

1. Genomic Variation Track Generation

Create tracks for visualizing genomic variations including SNPs, CNVs, and structural variants.

python

from scripts.main import CircosConfig

# Configuration for genomic variation plot
config = {
    "type": "variation",
    "title": "Sample Genomic Variations",
    "data": "variations.csv",
    "width": 1200,
    "height": 1200,
    "color_scheme": "nature",
    "output": "./circos_output"
}

# Generate configuration
generator = CircosConfig(config)
config_path = generator.generate()

print(f"Configuration generated: {config_path}")
print(f"Tracks included:")
print("  - Histogram track for SNPs/CNVs")
print("  - Link track for structural variants")
print("  - Chromosome ideogram")

Input Data Format:

Column	Description	Example
chrom	Chromosome name	chr1, chrX
start	Start position	1000000
end	End position	2000000
type	Variation type	SNP, CNV, TRANSLOCATION
value	Score or magnitude	0.5, -0.8
target_chrom	For SVs: target chromosome	chr5
target_start	For SVs: target start	5000000

Variation Types Supported:

Type	Visualization	Color Coding
SNP	Histogram points	Blue/Red (gain/loss)
CNV	Histogram bars	Green/Orange (amplification/deletion)
TRANSLOCATION	Links between chromosomes	Purple ribbons
INVERSION	Intra-chromosomal links	Yellow
DELETION	Histogram bars	Red
DUPLICATION	Histogram bars	Blue

Best Practices:

• ✅ Normalize values to -1 to +1 range for consistent scaling
• ✅ Use appropriate bin sizes (1-10 Mb) for genome-wide views
• ✅ Color code by type for easy interpretation
• ✅ Include ideogram for chromosome context

Common Issues and Solutions:

Issue: Too many data points causing clutter

• Symptom: Plot looks crowded with overlapping elements
• Solution: Increase bin size; filter for significant variants only; use transparency

Issue: Chromosome naming mismatch

• Symptom: Data not appearing on correct chromosomes
• Solution: Use consistent naming (chr1, chr2, ... chrX, chrY); check for "1" vs "chr1"

2. Cell-Cell Communication Visualization

Create circular plots showing interactions between cell types in tissues or tumors.

python

from scripts.main import CircosConfig

# Configuration for cell-cell communication
config = {
    "type": "cell-comm",
    "title": "Tumor Microenvironment Interactions",
    "data": "cell_communication.csv",
    "width": 1000,
    "height": 1000,
    "color_scheme": "cell",
    "output": "./cell_comm_plots"
}

generator = CircosConfig(config)
config_path = generator.generate()

print("Cell-cell communication plot configured:")
print("  - Cell types arranged in circle")
print("  - Connection ribbons showing interactions")
print("  - Labels for each cell type")

Input Format for Cell Communication:

Column	Description	Example
source	Source cell type	T_Cell
target	Target cell type	Macrophage
weight	Interaction strength (0-1)	0.8
type	Interaction type	Ligand-Receptor, Secreted

Visualization Features:

Feature	Description	Use Case
Ribbon links	Connection width ∝ interaction strength	Show communication intensity
Cell segments	Each cell type as chromosome segment	Compare cell type abundance
Labels	Cell type names outside circle	Identify cells easily
Colors	Distinct colors per cell type	Distinguish cell types

Best Practices:

• ✅ Normalize weights to 0-1 scale for consistent ribbon sizing
• ✅ Group related cell types together in input file
• ✅ Use distinct colors for each cell type (max 8-10 for clarity)
• ✅ Filter weak interactions (weight < 0.2) to reduce clutter

Common Issues and Solutions:

Issue: Too many cell types causing confusion

• Symptom: Plot crowded with >10 cell types
• Solution: Group rare cell types into "Other"; create separate plots for major groups

Issue: Bidirectional interactions not clear

• Symptom: Can't distinguish A→B from B→A
• Solution: Use arrow indicators; color-code by direction; split into two plots

3. Chromosome Ideogram Configuration

Generate chromosome ideograms showing banding patterns and genomic coordinates.

python

from scripts.main import CircosConfig, CHROMOSOME_SIZES

# View available chromosomes
print("Available chromosomes (GRCh38/hg38):")
for chrom, size in CHROMOSOME_SIZES.items():
    size_mb = size / 1_000_000
    print(f"  {chrom}: {size_mb:.1f} Mb")

# Custom chromosome selection
config = {
    "type": "variation",
    "title": "Chr1-5 Variations",
    "chromosomes": ["chr1", "chr2", "chr3", "chr4", "chr5"],  # Subset
    "width": 1000,
    "height": 1000,
    "output": "./chr1-5_plots"
}

# Note: Chromosome selection handled in data preprocessing

Chromosome Specifications:

Chromosome	Size (bp)	Display Color
chr1	248,956,422	Red
chr2	242,193,529	Orange
chr3	198,295,559	Yellow
...	...	...
chrX	156,040,895	Purple
chrY	57,227,415	Grey

Ideogram Features:

Feature	Description	Configuration
Spacing	Gap between chromosomes	0.005r (0.5% of radius)
Thickness	Chromosome bar width	25 pixels
Labels	Chromosome names	Outside circle
Bands	Cytogenetic bands	Show/hide option
Ticks	Scale markers	5u and 25u spacing

Best Practices:

• ✅ Include all autosomes for genome-wide views
• ✅ Show X and Y for sex chromosome analysis
• ✅ Use consistent scaling across samples
• ✅ Add cytoband information for clinical relevance

Common Issues and Solutions:

Issue: Small chromosomes (chr21, chrY) hard to see

• Symptom: Very small segments for small chromosomes
• Solution: Use non-linear scaling; create zoomed inset plots

Issue: Mitochondrial DNA not included

• Symptom: chrM variants not shown
• Solution: Add chrM to CHROMOSOME_SIZES dict; or exclude mitochondrial from plot

4. Multiple Track Layering

Overlay multiple data tracks in concentric circles for complex visualizations.

python

from scripts.main import CircosConfig

# Multi-track configuration
config = {
    "type": "custom",
    "title": "Multi-Track Genome View",
    "width": 1200,
    "height": 1200,
    "tracks": [
        {
            "type": "histogram",
            "file": "data/cnv_track.txt",
            "color": "color0"  # Red
        },
        {
            "type": "histogram", 
            "file": "data/snp_track.txt",
            "color": "color1"  # Blue
        },
        {
            "type": "link",
            "file": "data/sv_links.txt",
            "color": "color2"  # Green
        }
    ],
    "output": "./multi_track"
}

generator = CircosConfig(config)
config_path = generator.generate()

Track Positioning:

Track	Radius Range	Typical Use
Outer 1	0.95r - 0.80r	Primary data (CNVs)
Outer 2	0.80r - 0.65r	Secondary data (SNPs)
Middle	0.65r - 0.50r	Links/connections
Inner	0.50r - 0.35r	Annotations/labels

Track Types:

Type	Data Format	Best For
Histogram	chr start end value	Continuous values (CNVs, expression)
Scatter	chr start end value x y	Point data with categories
Heatmap	chr start end value0 value1...	Multi-sample comparisons
Link	chr1 start1 end1 chr2 start2 end2	Connections (SVs, interactions)
Text	chr start end label	Gene names, annotations

Best Practices:

• ✅ Limit to 3-4 tracks for readability
• ✅ Use complementary colors for different data types
• ✅ Add track labels in figure legend
• ✅ Consider track order - most important data outermost

Common Issues and Solutions:

Issue: Tracks overlapping

• Symptom: Data from different tracks hard to distinguish
• Solution: Adjust radius ranges; use different track types; add transparency

Issue: Scale differences between tracks

• Symptom: One track dominates visualization
• Solution: Normalize each track to 0-1 range; use separate color scales

5. Color Scheme Customization

Select from predefined color schemes or define custom colors for publication consistency.

python

from scripts.main import CircosConfig, COLOR_SCHEMES

# View available color schemes
print("Available color schemes:")
for name, colors in COLOR_SCHEMES.items():
    print(f"\n{name.upper()}:")
    print(f"  Colors: {', '.join(colors[:4])}...")

# Example outputs for each scheme
scheme_examples = {
    "default": ["red", "blue", "green", "orange"],
    "nature": ["#E64B35", "#4DBBD5", "#00A087", "#3C5488"],
    "lancet": ["#00468B", "#ED0000", "#42B540", "#0099B4"],
    "cell": ["#1B9E77", "#D95F02", "#7570B3", "#E7298A"]
}

# Usage
config = {
    "type": "variation",
    "color_scheme": "nature",  # Publication-quality colors
    # ... other config
}

Color Schemes:

Scheme	Style	Best For
default	Basic colors	Quick visualization, drafts
nature	Nature journal colors	Nature publications
lancet	Lancet journal colors	Medical/clinical papers
cell	Cell journal colors	Cell biology papers

Custom Colors:

python

# Define custom scheme
my_colors = ["#FF6B6B", "#4ECDC4", "#45B7D1", "#96CEB4", "#FFEAA7"]
COLOR_SCHEMES["custom"] = my_colors

config["color_scheme"] = "custom"

Best Practices:

• ✅ Use colorblind-friendly palettes for accessibility
• ✅ Match journal requirements for submissions
• ✅ Maintain consistency across all figures in paper
• ✅ Test printed output - colors may differ from screen

Common Issues and Solutions:

Issue: Colors not distinct enough

• Symptom: Hard to distinguish adjacent tracks
• Solution: Increase color contrast; use complementary colors

Issue: Colors don't match brand/institution

• Symptom: Need specific institutional colors
• Solution: Define custom color scheme with hex codes

6. Configuration Export and Rendering

Generate complete Circos configuration and optionally render the plot.

python

import subprocess
from pathlib import Path
from scripts.main import CircosConfig

def generate_and_render(config: dict, render: bool = False) -> dict:
    """
    Generate Circos config and optionally render plot.
    
    Returns:
        dict with paths and status
    """
    # Generate configuration
    generator = CircosConfig(config)
    config_path = generator.generate()
    
    result = {
        "config_path": config_path,
        "data_dir": str(generator.data_dir),
        "rendered": False,
        "output_image": None
    }
    
    # Attempt to render
    if render:
        output_dir = Path(config["output"])
        try:
            proc_result = subprocess.run(
                ["circos", "-conf", config_path],
                capture_output=True,
                text=True,
                cwd=output_dir
            )
            
            if proc_result.returncode == 0:
                result["rendered"] = True
                result["output_image"] = str(output_dir / "circos.png")
                print("✅ Plot rendered successfully!")
            else:
                print(f"❌ Rendering failed: {proc_result.stderr}")
        except FileNotFoundError:
            print("⚠️  Circos not installed. Configuration ready for manual rendering.")
            print(f"   Run: cd {output_dir} && circos -conf circos.conf")
    
    return result

# Example usage
config = {
    "type": "variation",
    "title": "Genomic Landscape",
    "data": "variants.csv",
    "output": "./output"
}

result = generate_and_render(config, render=True)

Output Files:

File	Description	Format
circos.conf	Main configuration	Text
data/karyotype.txt	Chromosome definitions	Text
data/*.txt	Track data files	TSV
circos.png	Raster image (if rendered)	PNG
circos.svg	Vector image (if rendered)	SVG

Rendering Requirements:

Component	Installation	Command
Circos	conda install -c bioconda circos	circos -conf circos.conf
Perl	Usually pre-installed	Required by Circos
GD library	System package	Image generation

Best Practices:

• ✅ Generate SVG for publication - scalable, editable
• ✅ Use PNG for drafts - faster rendering
• ✅ Check file sizes - high-res images can be large
• ✅ Archive configurations - for reproducibility

Common Issues and Solutions:

Issue: Circos installation fails

• Symptom: "circos: command not found"
• Solution: Use conda installation; check Perl and GD dependencies

Issue: Rendering produces warnings

• Symptom: Many "skip" or "warning" messages
• Solution: Usually harmless; check output image quality; adjust data ranges

---

Complete Workflow Example

From variant calls to publication figure:

bash

# Step 1: Create sample data for testing
python scripts/main.py --create-sample variation --output ./data

# Step 2: Generate configuration
python scripts/main.py \
  --data ./data/sample_variations.csv \
  --type variation \
  --title "Tumor Genomic Landscape" \
  --color-scheme nature \
  --width 1200 \
  --height 1200 \
  --output ./plots

# Step 3: Render plot (requires Circos)
python scripts/main.py \
  --data ./data/sample_variations.csv \
  --type variation \
  --output ./plots \
  --render

Python API Usage:

python

from scripts.main import CircosConfig
import pandas as pd

def create_genomic_landscape_plot(
    variation_data: pd.DataFrame,
    output_dir: str = "./circos_output",
    title: str = "Genomic Variations"
) -> str:
    """
    Create comprehensive genomic landscape Circos plot.
    
    Args:
        variation_data: DataFrame with columns [chrom, start, end, type, value]
        output_dir: Output directory for files
        title: Plot title
        
    Returns:
        Path to generated configuration file
    """
    # Save data to CSV
    data_path = f"{output_dir}/input_data.csv"
    variation_data.to_csv(data_path, index=False)
    
    # Generate configuration
    config = {
        "type": "variation",
        "title": title,
        "data": data_path,
        "width": 1200,
        "height": 1200,
        "color_scheme": "nature",
        "output": output_dir
    }
    
    generator = CircosConfig(config)
    config_path = generator.generate()
    
    # Print summary
    print(f"✅ Circos configuration generated")
    print(f"   Config: {config_path}")
    print(f"   Data directory: {generator.data_dir}")
    print(f"\nTo render:")
    print(f"   circos -conf {config_path}")
    
    return config_path

# Example with sample data
sample_data = pd.DataFrame({
    'chrom': ['chr1', 'chr1', 'chr2', 'chr5', 'chrX'],
    'start': [1000000, 5000000, 1000000, 5000000, 5000000],
    'end': [2000000, 6000000, 1500000, 7000000, 8000000],
    'type': ['SNP', 'CNV', 'SNP', 'TRANSLOCATION', 'DELETION'],
    'value': [0.5, -0.8, 0.3, None, -1.0],
    'target_chrom': [None, None, None, 'chr2', None],
    'target_start': [None, None, None, 8000000, None],
    'target_end': [None, None, None, 10000000, None]
})

config_file = create_genomic_landscape_plot(
    sample_data,
    output_dir="./my_plot",
    title="Sample Genomic Landscape"
)

Expected Output Files:

text

circos_output/
├── circos.conf              # Main configuration
├── data/
│   ├── karyotype.txt        # Chromosome definitions
│   ├── variations.txt       # Histogram data
│   └── links.txt            # Structural variant links
└── (after rendering)
    ├── circos.png           # Raster output
    └── circos.svg           # Vector output

---

Common Patterns

Pattern 1: Cancer Genomic Landscape

Scenario: Visualize genomic alterations in a tumor sample for publication.

json

{
  "plot_type": "variation",
  "title": "Tumor Genomic Landscape",
  "data_layers": [
    "CNV (outer track)",
    "SNV density (middle track)",
    "Structural variants (links)"
  ],
  "color_scheme": "nature",
  "resolution": "1200x1200",
  "publication": "Nature Medicine"
}

Workflow:

1. Collect CNV data from WGS or SNP array
2. Get SNV calls from exome/WGS
3. Identify structural variants (SVs)
4. Generate Circos configuration
5. Render and export high-resolution PNG/SVG
6. Create figure legend and methods description

Output Example:

text

Cancer Genomic Landscape Plot:
  - CNV track: 47 copy number alterations
  - SNV track: 2,847 mutations (density)
  - SV links: 12 translocations, 8 inversions
  
Key findings visible:
  - Chr8 MYC amplification
  - Chr17 TP53 deletion
  - Chr7-14 translocation
  
Publication ready: 1200x1200 PNG + SVG

Pattern 2: Tumor Microenvironment

Scenario: Visualize cell-cell communication in tumor microenvironment.

json

{
  "plot_type": "cell-comm",
  "title": "TME Communication Network",
  "cell_types": [
    "T_Cell", "B_Cell", "Macrophage",
    "NK_Cell", "Tumor_Cell", "Fibroblast"
  ],
  "data_source": "CellChat analysis",
  "filter": "weight > 0.3",
  "color_scheme": "cell"
}

Workflow:

1. Run CellChat or similar on scRNA-seq data
2. Export communication probabilities
3. Filter for significant interactions
4. Generate Circos configuration
5. Adjust colors for each cell type
6. Add annotations for key pathways

Output Example:

text

TME Communication Network:
  Cell types: 6
  Interactions: 24 (filtered from 156)
  
Major communication axes:
  - T_Cell → Macrophage (strongest)
  - Dendritic → T_Cell
  - Tumor → Macrophage
  
Insights:
  - Immunosuppressive signaling dominant
  - Limited NK cell activation

Pattern 3: Comparative Genomics

Scenario: Compare synteny between two species or strains.

json

{
  "plot_type": "custom",
  "title": "Human-Mouse Synteny",
  "tracks": [
    {
      "type": "link",
      "data": "synteny_blocks.txt",
      "description": "Conserved regions"
    }
  ],
  "genomes": ["hg38", "mm10"],
  "color_by": "chromosome"
}

Workflow:

1. Identify syntenic blocks between genomes
2. Map coordinates to common reference
3. Create link track for conserved regions
4. Generate dual-genome Circos plot
5. Color-code by chromosome of origin
6. Highlight breakpoints and rearrangements

Output Example:

text

Synteny Comparison:
  Human chromosomes: 22 + X + Y
  Mouse chromosomes: 19 + X + Y
  Syntenic blocks: 342
  
Key observations:
  - Chr12 conservation strong
  - Multiple breakpoints on Chr1
  - X chromosome largely conserved

Pattern 4: Time-Series Evolution

Scenario: Track clonal evolution through treatment timepoints.

json

{
  "plot_type": "custom",
  "title": "Clonal Evolution Over Time",
  "timepoints": ["Baseline", "Post-Treatment", "Relapse"],
  "tracks": [
    "Baseline CNV",
    "Post-Treatment CNV",
    "Relapse CNV",
    "Clonal links"
  ],
  "color_scheme": "lancet"
}

Workflow:

1. Collect CNV data from multiple timepoints
2. Track clone frequencies
3. Create separate track for each timepoint
4. Add links showing clone relationships
5. Generate evolution Circos plot
6. Annotate treatment events

Output Example:

text

Clonal Evolution Plot:
  Timepoints: 3
  Clones tracked: 5
  
Evolutionary trajectory:
  - Baseline: 3 subclones
  - Post-treatment: 1 dominant clone
  - Relapse: New clone emergence
  
Therapeutic implications:
  - Pre-existing resistance clone expanded
  - New mutation acquired at relapse

---

Quality Checklist

Data Preparation:

• CRITICAL: Verify chromosome naming consistency (chr1 vs 1)
• Check coordinate system (0-based vs 1-based)
• Validate all positions within chromosome bounds
• Normalize values to appropriate ranges
• Filter out low-quality or ambiguous data
• Ensure no duplicate entries
• Check for missing values and handle appropriately
• Verify file formats (CSV with proper headers)

Configuration:

• CRITICAL: Set appropriate image size for publication (min 1200x1200)
• Choose color scheme matching journal requirements
• Set track radii to avoid overlap
• Configure chromosome spacing for readability
• Add descriptive title
• Set up proper scaling for each track
• Choose appropriate color for each data type
• Test with subset of data first

Rendering:

• CRITICAL: Generate SVG for publication-quality output
• Check PNG output for visual quality
• Verify all tracks visible and correctly positioned
• Test color visibility (colorblind-friendly check)
• Confirm labels readable at target size
• Check for rendering warnings or errors
• Verify file sizes reasonable
• Archive configuration files

Publication:

• CRITICAL: Include scale bars and legends
• Add chromosome labels clearly
• Include figure caption with data description
• Note software version in methods
• Provide data availability statement
• Check journal figure requirements (size, format)
• Create supplementary data files if needed
• Test figure at print resolution

---

Common Pitfalls

Data Issues:

• ❌ Inconsistent chromosome names → Data missing from plot

  • ✅ Use consistent "chr" prefix (chr1, chr2, not 1, 2)

• ❌ Coordinates out of bounds → Rendering errors

  • ✅ Verify all coordinates ≤ chromosome size

• ❌ Too many data points → Cluttered, slow rendering

  • ✅ Filter for significance; increase bin size

• ❌ Missing values not handled → Gaps or errors

  • ✅ Impute or filter missing values before plotting

Configuration Issues:

• ❌ Tracks overlap → Data unreadable

  • ✅ Adjust radius ranges; use transparency

• ❌ Colors too similar → Can't distinguish tracks

  • ✅ Use distinct, contrasting colors

• ❌ Font too small → Labels unreadable

  • ✅ Increase font sizes for publication

• ❌ Image too small → Poor resolution

  • ✅ Use minimum 1200x1200 for publications

Interpretation Issues:

• ❌ No scale reference → Values unclear

  • ✅ Add color scale and value ranges

• ❌ Missing legend → Data types unexplained

  • ✅ Include comprehensive figure legend

• ❌ No chromosome labels → Location unclear

  • ✅ Label all chromosomes clearly

• ❌ Too much information → Figure overwhelming

  • ✅ Limit to 3-4 key data types per plot

---

Troubleshooting

Problem: Configuration generates but Circos won't render

• Symptoms: "Can't open file" or "Invalid configuration" errors
• Causes:
  • Missing data files
  • Incorrect file paths
  • Syntax errors in configuration
  • Missing Circos installation
• Solutions:
  • Verify all data files exist in data/ directory
  • Check file paths are absolute or correct relative paths
  • Validate configuration syntax
  • Install Circos: conda install -c bioconda circos

Problem: Plot is blank or missing data

• Symptoms: Chromosomes shown but no data tracks
• Causes:
  • Data format incorrect
  • Chromosome name mismatch
  • Values out of visible range
• Solutions:
  • Check data format matches expected (TSV, correct columns)
  • Verify chromosome names (chr1 vs 1)
  • Check min/max values in data files

Problem: Colors not as expected

• Symptoms: Wrong colors or all same color
• Causes:
  • Color scheme name misspelled
  • Custom colors not defined
  • Color values out of range
• Solutions:
  • Check color_scheme name matches available schemes
  • Define custom colors if needed
  • Verify color values are valid hex codes

Problem: Links/connections not showing

• Symptoms: Histograms visible but no SV links
• Causes:
  • Link data format incorrect
  • Target coordinates missing
  • Link radius outside visible area
• Solutions:
  • Check link file format: chr1 start1 end1 chr2 start2 end2
  • Verify target coordinates provided for translocations
  • Adjust link radius parameter

Problem: Text labels overlapping

• Symptoms: Gene names or labels unreadable
• Causes:
  • Too many labels in small space
  • Font size too large
  • Insufficient label radius
• Solutions:
  • Filter labels to show only most important
  • Reduce font size
  • Increase label radius (move further from center)
  • Use label collision detection if available

Problem: Rendering is very slow

• Symptoms: Takes minutes or hours to generate plot
• Causes:
  • Too many data points
  • High resolution settings
  • Complex link calculations
• Solutions:
  • Reduce data points (filter or bin)
  • Lower image resolution for drafts
  • Simplify link visualization
  • Use PNG instead of SVG for faster rendering

---

References

Available in references/ directory:

• (No reference files currently available for this skill)

External Resources:

• Circos Official Documentation: http://circos.ca/documentation
• Circos Tutorials: http://circos.ca/documentation/tutorials
• Bioconda Circos: https://bioconda.github.io/recipes/circos/README.html
• Nature Genetics Circos Examples: https://www.nature.com/ng/

---

Scripts

Located in scripts/ directory:

• main.py - Circos configuration generator with support for variations and cell communication

---

Color Scheme Reference

Default: red, blue, green, orange, purple, cyan

Nature: #E64B35, #4DBBD5, #00A087, #3C5488, #F39B7F, #8491B4

Lancet: #00468B, #ED0000, #42B540, #0099B4, #925E9F, #FDAF91

Cell: #1B9E77, #D95F02, #7570B3, #E7298A, #66A61E, #E6AB02

Parameters

Parameter	Type	Default	Required	Description
--data	string	-	Yes	Input data file (TSV/CSV format)
--output, -o	string	circos.svg	No	Output SVG file path
--type	string	variation	No	Plot type (variation, cell-communication)
--colors	string	default	No	Color scheme (default, nature, lancet, cell)
--radius	float	400	No	Plot radius in pixels
--help, -h	flag	-	No	Show help message

Usage

Basic Usage

bash

# Generate genomic variation Circos plot
python scripts/main.py --data variations.tsv --output genome.svg

# Cell communication plot with custom colors
python scripts/main.py --data cell_comm.tsv --type cell-communication --colors nature

# Custom radius
python scripts/main.py --data data.tsv --radius 500 --output large.svg

Input Data Format

Variation data (TSV format):

text

chromosome	position	value
chr1	1000000	0.5
chr1	2000000	-0.3
chr2	500000	0.8

Cell communication data (TSV format):

text

cell_type1	cell_type2	interaction_strength
T_cell	B_cell	0.75
Macrophage	T_cell	0.60

Risk Assessment

Risk Indicator	Assessment	Level
Code Execution	Python script executed locally	Low
Network Access	No external API calls	Low
File System Access	Read input data, write output SVG	Low
Data Exposure	Processes genomic data	Low
Resource Usage	Generates SVG files (can be large)	Low

Security Checklist

• No hardcoded credentials or API keys
• No unauthorized file system access
• Input validation for file paths
• Output directory restricted
• Error messages sanitized
• Script execution in sandboxed environment
• No network connections

Prerequisites

bash

# Python 3.7+
# No external packages required (uses standard library)
# Output: SVG format (viewable in web browsers)

Evaluation Criteria

Success Metrics

• Successfully generates Circos configuration
• Creates valid SVG output files
• Supports multiple color schemes
• Handles both variation and cell communication data

Test Cases

1. Variation Plot: Genomic data → Circular genome visualization
2. Cell Communication: Interaction matrix → Cell-type network diagram
3. Custom Colors: Data + color scheme → Styled visualization

Lifecycle Status

• Current Stage: Active
• Next Review Date: 2026-03-09
• Known Issues: None
• Planned Improvements:
  • Add more plot types (methylation, expression)
  • Support for interactive HTML output
  • Integration with common genomic formats (VCF, BED)

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Last Updated: 2026-02-09
Skill ID: 186
Version: 2.0 (K-Dense Standard)