write10xCounts {DropletUtils} | R Documentation

## Write count data in the 10x format

### Description

Create a directory containing the count matrix and cell/gene annotation from a sparse matrix of UMI counts, in the format produced by the CellRanger software suite.

### Usage

    write10xCounts(
      path,
      x,
      barcodes = colnames(x),
      gene.id = rownames(x),
      gene.symbol = gene.id,
      gene.type = "Gene Expression",
      overwrite = FALSE,
      type = c("auto", "sparse", "HDF5"),
      genome = "unknown",
      version = c("2", "3"),
      chemistry = "Single Cell 3' v3",
      original.gem.groups = 1L,
      library.ids = "custom"
    )

### Arguments

`path` | A string containing the path to the output directory (for `type="sparse"`) or file (for `type="HDF5"`).
`x` | A sparse numeric matrix of UMI counts.
`barcodes` | A character vector of cell barcodes, one per column of `x`.
`gene.id` | A character vector of gene identifiers, one per row of `x`.
`gene.symbol` | A character vector of gene symbols, one per row of `x`.
`gene.type` | A character vector of gene types, expanded to one per row of `x`. Only used when `version="3"`.
`overwrite` | A logical scalar specifying whether `path` should be overwritten if it already exists.
`type` | String specifying the type of 10X format to save `x` to. This is either a directory containing a sparse matrix with row/column annotation (`"sparse"`) or a HDF5 file containing the same information (`"HDF5"`).
`genome` | String specifying the genome for storage when `type="HDF5"`. This can be a character vector with one genome per feature if `version="3"`.
`version` | String specifying the version of the CellRanger format to produce.
`chemistry, original.gem.groups, library.ids` | Strings containing metadata attributes to be added to the HDF5 file for `type="HDF5"`. Their interpretation is not formally documented and is left to the user's imagination.

### Details

This function will try to automatically detect the desired format based on whether `path` ends with `".h5"`. If so, it assumes that `path` specifies a HDF5 file path and sets `type="HDF5"`. Otherwise it will set `type="sparse"` under the assumption that `path` specifies a path to a directory.

Note that there were major changes in the output format for CellRanger version 3.0 to account for non-gene features such as antibody or CRISPR tags. Users can switch to this new format using `version="3"`. See the documentation for “latest” for this new format, otherwise see “2.2” or earlier.

The primary purpose of this function is to create files to use for testing `read10xCounts`. In principle, it is possible to re-use the HDF5 matrices in `cellranger reanalyze`. We recommend against doing so routinely due to CellRanger's dependence on undocumented metadata attributes that may change without notice.

### Value

For `type="sparse"`, a directory is produced at `path`. If `version="2"`, this will contain the files `"matrix.mtx"`, `"barcodes.tsv"` and `"genes.tsv"`. If `version="3"`, it will instead contain `"matrix.mtx.gz"`, `"barcodes.tsv.gz"` and `"features.tsv.gz"`.

For `type="HDF5"`, a HDF5 file is produced at `path` containing data in column-sparse format. If `version="2"`, data are stored in the HDF5 group named `genome`. If `version="3"`, data are stored in the group `"matrix"`.

A `TRUE` value is invisibly returned.

### Author(s)

Aaron Lun

### References

10X Genomics (2017). Gene-Barcode Matrices. https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/2.2/output/matrices

10X Genomics (2018). Feature-Barcode Matrices. https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/latest/output/matrices

10X Genomics (2018). HDF5 Gene-Barcode Matrix Format. https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/2.2/advanced/h5_matrices

10X Genomics (2018). HDF5 Feature Barcode Matrix Format. https://support.10xgenomics.com/single-cell-gene-expression/software/pipelines/latest/advanced/h5_matrices

### See Also

`read10xCounts`, to read CellRanger matrices into R.

### Examples

    # Mocking up some count data.
    library(Matrix)
    my.counts <- matrix(rpois(1000, lambda=5), ncol=10, nrow=100)
    my.counts <- as(my.counts, "dgCMatrix")
    cell.ids <- paste0("BARCODE-", seq_len(ncol(my.counts)))

    ngenes <- nrow(my.counts)
    gene.ids <- paste0("ENSG0000", seq_len(ngenes))
    gene.symb <- paste0("GENE", seq_len(ngenes))

    # Writing this to file:
    tmpdir <- tempfile()
    write10xCounts(tmpdir, my.counts, gene.id=gene.ids,
        gene.symbol=gene.symb, barcodes=cell.ids)
    list.files(tmpdir)

    # Creating a version 3 HDF5 file:
    tmph5 <- tempfile(fileext=".h5")
    write10xCounts(tmph5, my.counts, gene.id=gene.ids,
        gene.symbol=gene.symb, barcodes=cell.ids, version='3')

[Package DropletUtils version 1.7.14 Index]