.byCtss {CAGEr} | R Documentation

## Apply functions to identical CTSSes.

### Description

`.byCTSS` is a private function using `data.table` objects to preform grouping operations at a high performance. These functions use non-standard evaluation in a context that raises warnings in `R CMD check`. By separating these functions from the rest of the code, I hope to make the workarounds easier to manage.

### Usage

    .byCtss(ctssDT, colName, fun)

    ## S4 method for signature 'data.table'
    .byCtss(ctssDT, colName, fun)

### Arguments

`ctssDT` | A `data.table` representing CTSSes.
`colName` | The name of the column on which to apply the function.
`fun` | The function to apply.

### Examples

    ctssDT <- data.table::data.table(
      chr       = c("chr1", "chr1", "chr1", "chr2"),
      pos       = c(1     , 1     , 2     , 1     ),
      strand    = c("+"   , "+"   , "-"   , "-"   ),
      tag_count = c(1     , 1     , 1     , 1     ))
    ctssDT
    CAGEr:::.byCtss(ctssDT, "tag_count", sum)

[Package CAGEr version 2.0.2 Index]