Hic Normalization

Overview

This skill performs Hi-C data normalization on .mcool files.
Main steps include:

• Refer to the Inputs & Outputs section to verify required files and output structure.
• Check normalization status per resolution (supports bins/weight columns only).
• If a resolution is not normalized, perform normalization with cooler balance (ICE) to create bins/weight.
• Verify normalization and emit a concise report on the file, resolution, and normalization status.

When to use this skill

Use the hic-normalization pipeline when:

• You need to ensure that Hi-C data is normalized for downstream analysis.
• Your data comes in .cool or .mcool formats, and you want to check or refresh normalization status (ICE normalization).

This tool assumes the file already has correct genome assembly and chromosome names.

Inputs & Outputs

Inputs

• Accepted file format: .mcool

Outputs

${sample}_hic_norm/
    ${sample}_norm.mcool
    normalization_report.txt  # A brief log/report indicating which resolutions were detected, normalized, or skipped.

Decision Tree

Step 0 — Gather Required Information from the User

Before calling any tool, ask the user:

1. Sample name (sample): used as prefix and for the output directory ${sample}_hic_norm.
2. Genome assembly (genome): e.g. hg38, mm10, danRer11.
   • Never guess or auto-detect.
3. Hi-C matrix path (mcool_path): e.g. .mcool file path or .hic file path.
   • path/to/sample.mcool (.mcool file without resolution specified)
   • or .hic file path

Step 1: Initialize Project

1. Make director for this project:

Call:

• mcp__project-init-tools__project_init

with:

• sample: the user-provided sample name
• task: hic_norm

The tool will:

• Create ${sample}_hic_norm directory.
• Get the full path of the ${sample}_hic_norm directory, which will be used as ${proj_dir}.

2. If the user provides a .hic file, convert it to .mcool file first using mcp__HiCExplorer-tools__hic_to_mcool tool:

Call:

• mcp__HiCExplorer-tools__hic_to_mcool

with:

• input_hic: the user-provided path (e.g. input.hic)
• sample: the user-provided sample name
• proj_dir: directory to save the view file. In this skill, it is the full path of the ${sample}_hic_norm directory returned by mcp__project-init-tools__project_init.
• resolutions: the user-provided resolutions (e.g. [50000])

The tool will:

• Convert the .hic file to .mcool file.
• Return the path of the .mcool file.

If the conversion is successful, update ${mcool_uri} to the path of the .mcool file. The ${mcool_path} should be updated to the path of the .mcool file without resolution specified.

3. Inspect the .mcool file to list available resolutions and confirm the analysis resolution with the user.

Call:

• mcp__cooler-tools__list_mcool_resolutions

with:

• mcool_path: the user-provided path (e.g. input.mcool) or the path of the .mcool file returned by mcp__HiCExplorer-tools__hic_to_mcool

The tool will:

• List all resolutions in the .mcool file.
• Return the resolutions as a list.

Step 2: Check Normalization Status (per resolution) on .mcool and normlize if missing

Call:

• mcp__cooler-tools__check_and_balance_mcool

with:

• sample: the user-provided sample name
• proj_dir: the full path to the project directory
• mcool_path: the path to the .mcool file (e.g. input.mcool) without resolution specified.
• balance_missing: if true, run cooler.balance_cooler on resolutions missing /bins/weight
• store_name: the name of the weight column to write into bins (default: 'weight')
• ignore_diags: the number of diagonals to ignore (ignore_diags in cooler.balance_cooler)
• mad_max: the mad_max parameter for cooler.balance_cooler (default: cooler's own)
• converge: the convergence tolerance, maps to tol in cooler.balance_cooler
• max_iters: the max_iters parameter for cooler.balance_cooler
• cis_only: if true, balance cis contacts only (cis_only=True)

The tool will:

• Check the normalization status (per resolution) on the .mcool file.
• If the normalization is missing, balance the .mcool file.
• Return the path of the balanced .mcool file under ${proj_dir}/ directory.

Notes & Troubleshooting

• Normalization fails to converge: Increase iterations or adjust the convergence criteria (--max-iters, --converge)