Define where the pipeline should find input data and save output data.

Input FastQ files

type: string

Use this to specify the location of your input FastQ files. For example:

--input 'path/to/data/sample_*_{1,2}.fastq'  

Please note the following requirements:

  1. The path must be enclosed in quotes
  2. The path must have at least one * wildcard character
  3. When using the pipeline with paired end data, the path must use {1,2} notation to specify read pairs.

If left unspecified, a default pattern is used: data/*{1,2}.fastq.gz

Input FastQ files path in array format

hidden
type: string

The output directory where the results will be saved.

type: string
default: ./results

Email address for completion summary.

type: string
pattern: ^([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5})$

Set this parameter to your e-mail address to get a summary e-mail with details of the run sent to you when the workflow exits. If set in your user config file (~/.nextflow/config) then you don't need to specify this on the command line for every run.

Name of droplet technology (Currently supported: 10x, Drop-Seq, inDrop, etc may be supported in the future.)

type: string
default: 10x

Version of 10x chemistry

type: string
default: V3

To specify which chemistry (and thus barcode whitelist) to use, use the --chemistry flag. For example, to specify V3 chemistry (the default, as it is compatible with V2), use --chemistry V3.

These files were copied out of 10x Genomics' cellranger cellranger/lib/python/cellranger/barcodes, in some cases gzipped for simplicity across versions, and copied to assets/whitelist.

  • V1: 737K-april-2014_rc.txt --> gzipped --> 10x_V1_barcode_whitelist.txt.gz
  • V2: 737K-august-2016.txt --> gzipped --> 10x_V2_barcode_whitelist.txt.gz
  • V3: 3M-february-2018.txt.gz --> 10x_V3_barcode_whitelist.txt.gz

If not using the 10X Genomics platform, a custom barcode whitelist can be used with --barcode_whitelist.

type: string

Name of the tool to use for scRNA (pseudo-) alignment. Available are: "alevin", "star", "kallisto". Default 'alevin'.

type: string
default: alevin

The workflow can handle three types of methods:

  • Kallisto/Bustools
  • Salmon Alevin + AlevinQC
  • STARsolo

To choose which one to use, please specify either alevin, star or kallisto as a parameter option for --aligner. By default, the pipeline runs the alevin option. Note that specifying another aligner option also requires choosing appropriate parameters (see below) for the selected option.

Options for the reference genome indices used to align reads.

Name of iGenomes reference.

type: string

If using a reference genome configured in the pipeline using iGenomes, use this parameter to give the ID for the reference. This is then used to build the full paths for all required reference genome files e.g. --genome GRCh38.

See the nf-core website docs for more details.

Path to FASTA genome file.

type: string

If you have no genome reference available, the pipeline can build one using a FASTA file. This requires additional time and resources, so it's better to use a pre-build index if possible.

Directory / URL base for iGenomes references.

hidden
type: string
default: s3://ngi-igenomes/igenomes/

Do not load the iGenomes reference config.

hidden
type: boolean

Do not load igenomes.config when running the pipeline. You may choose this option if you observe clashes between custom parameters and those supplied in igenomes.config.

A cDNA fastq file

type: string

Reference GTF annotation file

type: string

Specify this parameter to save the indices created (STAR, Kallisto, Salmon) to the results.

type: string

This can be used to specify a precomputed Salmon index in the pipeline, in order to skip the generation of required indices by Salmon itself.

type: string

Path to transcript to gene mapping file. This allows the specification of a transcript to gene mapping file for Salmon Alevin and AlevinQC.

type: string

This is not the same as the kallisto_gene_map parameter down below and is only used by the Salmon Alevin workflow.

Specify a path to the precomputed STAR index.

type: string

NB: This has to be computed with STAR Version 2.7 or later, as STARsolo was only first supported by STAR Version 2.7.

Params related to Kallisto/BUS tool

Specify a Kallisto gene mapping file here. If you don't, this will be automatically created in the Kallisto workflow when specifying a valid --gtf file.

type: string

If set to false, skip the correct steps after mapping with Kallisto.

type: boolean

Skip BUStools entirely in workflow

type: boolean

Specify a path to the precomputed Kallisto index.

type: string

Less common options for the pipeline, typically set in a config file.

Display help text.

hidden
type: boolean

Method used to save pipeline results to output directory.

hidden
type: string

The Nextflow publishDir option specifies which intermediate files should be saved to the output directory. This option tells the pipeline what method should be used to move these files. See Nextflow docs for details.

Boolean whether to validate parameters against the schema at runtime

hidden
type: boolean
default: true

Email address for completion summary, only when pipeline fails.

hidden
type: string
pattern: ^([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5})$

This works exactly as with --email, except emails are only sent if the workflow is not successful.

Send plain-text email instead of HTML.

hidden
type: boolean

Set to receive plain-text e-mails instead of HTML formatted.

File size limit when attaching MultiQC reports to summary emails.

hidden
type: string
default: 25.MB

If file generated by pipeline exceeds the threshold, it will not be attached.

Do not use coloured log outputs.

hidden
type: boolean

Set to disable colourful command line output and live life in monochrome.

Custom config file to supply to MultiQC.

hidden
type: string

Directory to keep pipeline Nextflow logs and reports.

hidden
type: string
default: ${params.outdir}/pipeline_info

Show all params when using --help

hidden
type: boolean

By default, parameters set as hidden in the schema are not shown on the command line when a user runs with --help. Specifying this option will tell the pipeline to show all parameters.

Set the top limit for requested resources for any single job.

Maximum number of CPUs that can be requested for any single job.

hidden
type: integer
default: 16

Use to set an upper-limit for the CPU requirement for each process. Should be an integer e.g. --max_cpus 1

Maximum amount of memory that can be requested for any single job.

hidden
type: string
default: 128.GB
pattern: ^[\d\.]+\s*.(K|M|G|T)?B$

Use to set an upper-limit for the memory requirement for each process. Should be a string in the format integer-unit e.g. --max_memory '8.GB'

Maximum amount of time that can be requested for any single job.

hidden
type: string
default: 240.h
pattern: ^[\d\.]+\.*(s|m|h|d)$

Use to set an upper-limit for the time requirement for each process. Should be a string in the format integer-unit e.g. --max_time '2.h'

Parameters used to describe centralised config profiles. These should not be edited.

Git commit id for Institutional configs.

hidden
type: string
default: master

Provide git commit id for custom Institutional configs hosted at nf-core/configs. This was implemented for reproducibility purposes. Default: master.

## Download and use config file with following git commit id  
--custom_config_version d52db660777c4bf36546ddb188ec530c3ada1b96  

Base directory for Institutional configs.

hidden
type: string
default: https://raw.githubusercontent.com/nf-core/configs/master

If you're running offline, nextflow will not be able to fetch the institutional config files from the internet. If you don't need them, then this is not a problem. If you do need them, you should download the files from the repo and tell nextflow where to find them with the custom_config_base option. For example:

## Download and unzip the config files  
cd /path/to/my/configs  
wget https://github.com/nf-core/configs/archive/master.zip  
unzip master.zip  
  
## Run the pipeline  
cd /path/to/my/data  
nextflow run /path/to/pipeline/ --custom_config_base /path/to/my/configs/configs-master/  

Note that the nf-core/tools helper package has a download command to download all required pipeline files + singularity containers + institutional configs in one go for you, to make this process easier.

Institutional configs hostname.

hidden
type: string

Institutional config name.

hidden
type: string

Institutional config description.

hidden
type: string

Institutional config contact information.

hidden
type: string

Institutional config URL link.

hidden
type: string