hmmsim

Use when you need to characterize score distributions of a profile HMM on random sequences, such as calibration checks, benchmarking, or filter-behavior experiments.

SKILL.md

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hmmsim

Quick Start

  • Command: hmmsim [options] <hmmfile>
  • Local executable: /home/vimalinx/miniforge3/envs/bio/bin/hmmsim
  • Full reference: See references/help.md

When To Use This Tool

  • Measure how a profile HMM scores random sequences.
  • Explore score and E-value behavior under different random-sequence lengths and sample counts.
  • Benchmark HMM filtering or calibration behavior before deploying a profile in larger search pipelines.
  • Generate score-distribution outputs for debugging or method development around HMMER models.

Common Patterns

# 1) Collect a basic score distribution for one profile HMM
hmmsim \
  mymodel.hmm
# 2) Increase the number and length of random targets
hmmsim \
  -N 10000 \
  -L 300 \
  mymodel.hmm
# 3) Write verbose scores and an E-value calibration plot payload
hmmsim \
  -v \
  --efile hmmsim.eplot.tsv \
  -o hmmsim.out \
  mymodel.hmm

Recommended Workflow

  1. Prepare a valid profile HMM file and decide whether you need a quick default run or a larger calibration experiment with explicit -N and -L.
  2. Choose the scoring/alignment mode (--vit, --fwd, --hyb, --msv, --fs, --sw, --ls, --s) if you are studying a specific HMMER behavior.
  3. Run hmmsim and direct outputs to files with -o, --efile, --ffile, or related options when you want reusable diagnostic artifacts.
  4. Interpret the result as a random-sequence score-distribution study, not as a biologically realistic sequence-generation workflow.

Guardrails

  • hmmsim evaluates an HMM against random sequences; it is not a general simulator for generating biologically realistic sequences from a model.
  • Use -h for help; --help and --version are not supported.
  • The input must be a valid HMMER profile HMM file.
  • Defaults are relatively small (-N 1000, -L 100), so set them explicitly for serious calibration or benchmarking work.