Gen Random Reads

gen-random-reads

Quick Start

• Command: genRandomReads ...
• Local executable: /home/vimalinx/miniforge3/envs/bio/bin/genRandomReads
• Two main modes: --summarizeFasta for transcript lengths, or read generation with --transcriptFasta, --outputPrefix, and --expressionLevels

When To Use This Tool

• Simulate single-end or paired-end transcriptomic reads from a transcript FASTA.
• Build synthetic RNA-seq datasets from transcript-level TPM values for benchmarking.
• Summarize transcript names and lengths before constructing the TPM table.
• Encode ground-truth origins in read names when testing alignment or quantification pipelines.

Common Patterns

# 1) Summarize transcript IDs and lengths from a FASTA file
genRandomReads \
  --summarizeFasta \
  --transcriptFasta transcripts.fa \
  --outputPrefix tx_summary

# 2) Generate single-end reads from a TPM table
genRandomReads \
  --transcriptFasta transcripts.fa \
  --outputPrefix sim_reads \
  --expressionLevels tpm.tsv \
  --totalReads 500000

# 3) Generate paired-end reads and preserve truth in read names
genRandomReads \
  --transcriptFasta transcripts.fa \
  --outputPrefix sim_pe \
  --expressionLevels tpm.tsv \
  --totalReads 200000 \
  --pairedEnd \
  --truthInReadNames

Recommended Workflow

1. Run --summarizeFasta first so you know the available transcript IDs and lengths.
2. Build the required two-column tab-delimited expression file: TranscriptID<TAB>TPM.
3. Decide on read length, total reads, and whether you need paired-end simulation or truth labels in the read names.
4. Generate the dataset, then inspect the created files before feeding them into downstream aligners or quantifiers.

Guardrails

• For read generation, --transcriptFasta, --outputPrefix, and --expressionLevels are required; omitting --totalReads triggers a warning and defaults to one million reads.
• --help is not a clean help path: it is reported as an unrecognized option before the usage block is printed.
• The expression file must be tab-delimited with transcript ID in column 1 and TPM in column 2.
• --qualityRefFile expects Phred+33 strings whose lengths match --readLen.
• --simpleTranscriptId truncates transcript names at the first | or space, which can change identifier matching if used carelessly.
• The transcript FASTA can be plain or gzipped (FASTA/gz in the usage text).