Function reference • data.table

All functions
`as.IDate()` `as.Date(<IDate>)` `as.POSIXct(<IDate>)` `round(<IDate>)` `as.ITime()` `as.POSIXct(<ITime>)` `as.character(<ITime>)` `format(<ITime>)` `IDateTime()` `second()` `minute()` `hour()` `yday()` `wday()` `mday()` `week()` `isoweek()` `month()` `quarter()` `year()`	Integer based date class
`SJ()` `CJ()`	Creates a join `data.table`
`address()`	Address in RAM of a variable
`all.equal(<data.table>)`	Equality Test Between Two Data Tables
`as.data.table()` `is.data.table()`	Coerce to data.table
`as.data.table(<xts>)`	Efficient xts to as.data.table conversion
`as.matrix(<data.table>)`	Convert a data.table to a matrix
`as.xts.data.table()`	Efficient data.table to xts conversion
`set()`	Assignment by reference
`between()` `%between%` `inrange()` `%inrange%`	Convenience functions for range subsets.
`chmatch()` `%chin%` `chorder()` `chgroup()`	Faster match of character vectors
`fcoalesce()`	Coalescing missing values
`copy()`	Copy an entire object
`data.table-class`	S4 Definition for data.table
`data.table()` `[`(<data.table>)	Enhanced data.frame
`datatable.optimize`	Optimisations in data.table
`dcast(<data.table>)`	Fast dcast for data.table
`duplicated(<data.table>)` `unique(<data.table>)` `anyDuplicated(<data.table>)` `uniqueN()`	Determine Duplicate Rows
`fifelse()`	Fast ifelse
`foverlaps()`	Fast overlap joins
`frank()` `frankv()`	Fast rank
`fread()`	Fast and friendly file finagler
`frollmean()` `frollsum()` `frollapply()`	Rolling functions
`fsort()`	Fast parallel sort
`fwrite()`	Fast CSV writer
`rollup()` `cube()` `groupingsets()`	Grouping Set aggregation for data tables
`first()` `last()`	First/last item of an object
`.Last.updated`	Number of rows affected by last update
`like()` `%like%` `%ilike%` `%flike%`	Convenience function for calling grep.
`melt(<data.table>)`	Fast melt for data.table
`merge(<data.table>)`	Merge two data.tables
`na.omit(<data.table>)`	Remove rows with missing values on columns specified
`nafill()` `setnafill()`	Fill missing values
`setDTthreads()` `getDTthreads()`	Set or get number of threads that data.table should use
`patterns()`	Obtain matching indices corresponding to patterns
`print(<data.table>)`	data.table Printing Options
`rbindlist()`	Makes one data.table from a list of many
`rleid()` `rleidv()`	Generate run-length type group id
`rowid()` `rowidv()`	Generate unique row ids within each group
`setDF()`	Coerce a data.table to data.frame by reference
`setDT()`	Coerce lists and data.frames to data.table by reference
`setNumericRounding()` `getNumericRounding()`	Change or turn off numeric rounding
`setattr()` `setnames()`	Set attributes of objects by reference
`setcolorder()`	Fast column reordering of a data.table by reference
`setkey()` `setkeyv()` `setindex()` `setindexv()` `key()` `indices()` `haskey()`	Create key on a data.table
`fintersect()` `fsetdiff()` `funion()` `fsetequal()`	Set operations for data tables
`setorder()` `setorderv()`	Fast row reordering of a data.table by reference
`shift()`	Fast lead/lag for vectors and lists
`shouldPrint()`	For use by packages that mimic/divert auto printing e.g. IRkernel and knitr
`special-symbols`	Special symbols
`split(<data.table>)`	Split data.table into chunks in a list
`subset(<data.table>)`	Subsetting data.tables
`tables()`	Display 'data.table' metadata
`test()`	Test assertions for equality, exceptions and console output
`test.data.table()`	Runs a set of tests.
`timetaken()`	Pretty print of time taken
`transpose()`	Efficient transpose of list
`truelength()` `setalloccol()` `alloc.col()`	Over-allocation access
`tstrsplit()`	strsplit and transpose the resulting list efficiently
`update(<dev.pkg>)`	Perform update of development version of a package

Reference

All functions

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