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data.table.R
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data.table.R
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dim.data.table = function(x)
{
.Call(Cdim, x)
}
.global = new.env() # thanks to: http://stackoverflow.com/a/12605694/403310
methods::setPackageName("data.table",.global)
.global$print = ""
# NB: if adding to/editing this list, be sure to do the following:
# (1) add to man/special-symbols.Rd
# (2) export() in NAMESPACE
# (3) add to vignettes/datatable-importing.Rmd#globals section
.SD = .N = .I = .GRP = .NGRP = .BY = .EACHI = NULL
# These are exported to prevent NOTEs from R CMD check, and checkUsage via compiler.
# But also exporting them makes it clear (to users and other packages) that data.table uses these as symbols.
# And NULL makes it clear (to the R's mask check on loading) that they're variables not functions.
# utils::globalVariables(c(".SD",".N")) was tried as well, but exporting seems better.
# So even though .BY doesn't appear in this file, it should still be NULL here and exported because it's
# defined in SDenv and can be used by users.
is.data.table = function(x) inherits(x, "data.table")
is.ff = function(x) inherits(x, "ff") # define this in data.table so that we don't have to require(ff), but if user is using ff we'd like it to work
#NCOL = function(x) {
# # copied from base, but additionally covers data.table via is.list()
# # because NCOL in base explicitly tests using is.data.frame()
# if (is.list(x) && !is.ff(x)) return(length(x))
# if (is.array(x) && length(dim(x)) > 1L) ncol(x) else as.integer(1L)
#}
#NROW = function(x) {
# if (is.data.frame(x) || is.data.table(x)) return(nrow(x))
# if (is.list(x) && !is.ff(x)) stopf("List is not a data.frame or data.table. Convert first before using NROW") # list may have different length elements, which data.table and data.frame's resolve.
# if (is.array(x)) nrow(x) else length(x)
#}
null.data.table = function() {
ans = list()
setattr(ans,"class",c("data.table","data.frame"))
setattr(ans,"row.names",.set_row_names(0L))
setalloccol(ans)
}
data.table = function(..., keep.rownames=FALSE, check.names=FALSE, key=NULL, stringsAsFactors=FALSE)
{
# NOTE: It may be faster in some circumstances for users to create a data.table by creating a list l
# first, and then setattr(l,"class",c("data.table","data.frame")) and forgo checking.
x = list(...) # list() doesn't copy named inputs as from R >= 3.1.0 (a very welcome change)
nd = name_dots(...)
names(x) = nd$vnames
if (length(x)==0L) return( null.data.table() )
if (length(x)==1L && (is.null(x[[1L]]) || (is.list(x[[1L]]) && length(x[[1L]])==0L))) return( null.data.table() ) #48
ans = as.data.table.list(x, keep.rownames=keep.rownames, check.names=check.names, .named=nd$.named) # see comments inside as.data.table.list re copies
if (!is.null(key)) {
if (!is.character(key)) stopf("key argument of data.table() must be character")
if (length(key)==1L) key = cols_from_csv(key)
setkeyv(ans,key)
} else {
# retain key of cbind(DT1, DT2, DT3) where DT2 is keyed but not DT1. cbind calls data.table().
# If DT inputs with keys have been recycled then can't retain key
ckey = NULL
for (i in seq_along(x)) {
xi = x[[i]]
if (is.data.table(xi) && haskey(xi) && nrow(xi)==nrow(ans)) ckey=c(ckey, key(xi))
}
if (length(ckey) &&
!anyDuplicated(ckey) &&
identical(is.na(chmatchdup(c(ckey,ckey), names(ans))), rep(c(FALSE,TRUE),each=length(ckey)))) {
setattr(ans, "sorted", ckey)
}
}
if (isTRUE(stringsAsFactors)) {
for (j in which(vapply_1b(ans, is.character))) set(ans, NULL, j, as_factor(.subset2(ans, j)))
# as_factor is internal function in fread.R currently
}
setalloccol(ans) # returns a NAMED==0 object, unlike data.frame()
}
replace_dot_alias = function(e) {
# we don't just simply alias .=list because i) list is a primitive (faster to iterate) and ii) we test for use
# of "list" in several places so it saves having to remember to write "." || "list" in those places
if (is.call(e) && !is.function(e[[1L]])) {
# . alias also used within bquote, #1912
if (e[[1L]] == 'bquote') return(e)
if (e[[1L]] == ".") e[[1L]] = quote(list)
for (i in seq_along(e)[-1L]) if (!is.null(e[[i]])) e[[i]] = replace_dot_alias(e[[i]])
}
e
}
.massagei = function(x) {
# J alias for list as well in i, just if the first symbol
# if x = substitute(base::order) then as.character(x[[1L]]) == c("::", "base", "order")
if (x %iscall% c("J","."))
x[[1L]] = quote(list)
x
}
.checkTypos = function(err, ref) {
# a slightly wonky workaround so that this still works in non-English sessions, #4989
# generate this at run time (as opposed to e.g. onAttach) since session language is
# technically OK to update (though this should be rare), and since it's low-cost
# to do so here because we're about to error anyway.
missing_obj_fmt = gsub(
"'missing_datatable_variable____'",
"'(?<obj_name>[^']+)'",
tryCatch(eval(parse(text="missing_datatable_variable____")), error=identity)$message
# eval(parse()) to avoid "no visible binding for global variable" note from R CMD check
# names starting with _ don't parse, so no leading _ in the name
)
idx <- regexpr(missing_obj_fmt, err$message, perl=TRUE)
if (idx > 0L) {
start = attr(idx, "capture.start", exact=TRUE)[ , "obj_name"]
used = substr(
err$message,
start,
start + attr(idx, "capture.length", exact=TRUE)[ , "obj_name"] - 1L
)
found = agrep(used, ref, value=TRUE, ignore.case=TRUE, fixed=TRUE)
if (length(found)) {
stopf("Object '%s' not found. Perhaps you intended %s", used, brackify(found))
} else {
stopf("Object '%s' not found amongst %s", used, brackify(ref))
}
} else {
stopf(err$message)
}
}
"[.data.table" = function(x, i, j, by, keyby, with=TRUE, nomatch=NA, mult="all", roll=FALSE, rollends=if (roll=="nearest") c(TRUE,TRUE) else if (roll>=0) c(FALSE,TRUE) else c(TRUE,FALSE), which=FALSE, .SDcols, verbose=getOption("datatable.verbose"), allow.cartesian=getOption("datatable.allow.cartesian"), drop=NULL, on=NULL, env=NULL, showProgress=getOption("datatable.showProgress", interactive()))
{
# ..selfcount <<- ..selfcount+1 # in dev, we check no self calls, each of which doubles overhead, or could
# test explicitly if the caller is [.data.table (even stronger test. TO DO.)
# the drop=NULL is to sink drop argument when dispatching to [.data.frame; using '...' stops test 147
if (!cedta()) {
# Fix for #500 (to do)
if (substitute(j) %iscall% c(":=", "let")) {
# Throw a specific error message
stopf("[ was called on a data.table in an environment that is not data.table-aware (i.e. cedta()), but '%s' was used, implying the owner of this call really intended for data.table methods to be called. See vignette('datatable-importing') for details on properly importing data.table.", as.character(substitute(j)[[1L]]))
}
Nargs = nargs() - (!missing(drop))
ans = if (Nargs<3L) { `[.data.frame`(x,i) } # drop ignored anyway by DF[i]
else if (missing(drop)) `[.data.frame`(x,i,j)
else `[.data.frame`(x,i,j,drop)
# added is.data.table(ans) check to fix bug #81
if (!missing(i) && is.data.table(ans)) setkey(ans, NULL) # drops index too; tested by plyr::arrange test in other.Rraw
return(ans)
}
if (!missing(verbose)) {
if (!is.integer(verbose) && !is.logical(verbose)) stopf("verbose must be logical or integer")
if (length(verbose)!=1 || anyNA(verbose)) stopf("verbose must be length 1 non-NA")
# set the global verbose option because that is fetched from C code without having to pass it through
oldverbose = options(datatable.verbose=verbose)
on.exit(options(oldverbose))
}
.global$print=""
missingby = missing(by) && missing(keyby) # for tests 359 & 590 where passing by=NULL results in data.table not vector
if (missingby || missing(j)) {
if (!missingby) warningf("Ignoring by/keyby because 'j' is not supplied")
by = bysub = NULL
keyby = FALSE
} else {
if (missing(by)) {
by = bysub = if (is.null(env)) substitute(keyby)
else eval(substitute(substitute2(.keyby, env), list(.keyby = substitute(keyby))))
keyby = TRUE
} else {
by = bysub = if (is.null(env)) substitute(by)
else eval(substitute(substitute2(.by, env), list(.by = substitute(by))))
if (missing(keyby))
keyby = FALSE
else if (!isTRUEorFALSE(keyby))
stopf("When by and keyby are both provided, keyby must be TRUE or FALSE")
}
if (missing(by)) { missingby=TRUE; by=bysub=NULL } # possible when env is used, PR#4304
else if (verbose && !is.null(env)) catf("Argument '%s' after substitute: %s\n", "by", paste(deparse(bysub, width.cutoff=500L), collapse=" "))
}
bynull = !missingby && is.null(by) #3530
byjoin = !is.null(by) && is.symbol(bysub) && bysub==".EACHI"
naturaljoin = FALSE
names_x = names(x)
if (missing(i) && !missing(on)) {
tt = eval.parent(.massagei(substitute(on)))
if (!is.list(tt) || !length(names(tt))) {
warningf("When on= is provided but not i=, on= must be a named list or data.table|frame, and a natural join (i.e. join on common names) is invoked. Ignoring on= which is '%s'.", class(tt)[1L])
on = NULL
} else {
i = tt
naturaljoin = TRUE
}
}
if (missing(i) && missing(j)) {
tt_isub = substitute(i)
tt_jsub = substitute(j)
if (!is.null(names(sys.call())) && # not relying on nargs() as it considers DT[,] to have 3 arguments, #3163
tryCatch(!is.symbol(tt_isub), error=function(e)TRUE) && # a symbol that inherits missingness from caller isn't missing for our purpose; test 1974
tryCatch(!is.symbol(tt_jsub), error=function(e)TRUE)) {
warningf("i and j are both missing so ignoring the other arguments. This warning will be upgraded to error in future.")
}
return(x)
}
if (!mult %chin% c("first","last","all")) stopf("mult argument can only be 'first', 'last' or 'all'")
missingroll = missing(roll)
if (length(roll)!=1L || is.na(roll)) stopf("roll must be a single TRUE, FALSE, positive/negative integer/double including +Inf and -Inf or 'nearest'")
if (is.character(roll)) {
if (roll!="nearest") stopf("roll is '%s' (type character). Only valid character value is 'nearest'.", roll)
} else {
roll = if (isTRUE(roll)) +Inf else as.double(roll)
}
force(rollends)
if (!is.logical(rollends)) stopf("rollends must be a logical vector")
if (length(rollends)>2L) stopf("rollends must be length 1 or 2")
if (length(rollends)==1L) rollends=rep.int(rollends,2L)
# TO DO (document/faq/example). Removed for now ... if ((roll || rolltolast) && missing(mult)) mult="last" # for when there is exact match to mult. This does not control cases where the roll is mult, that is always the last one.
.unsafe.opt() #3585
missingnomatch = missing(nomatch)
nomatch0 = identical(nomatch,0) || identical(nomatch,0L) || identical(nomatch, FALSE) # for warning with row-numbers in i; #4353
if (nomatch0) nomatch=NULL # retain nomatch=0|FALSE backwards compatibility, #857 #5214
if (!is.null(nomatch)) {
if (!(length(nomatch)==1L && is.na(nomatch))) stopf("nomatch= must be either NA or NULL (or 0 for backwards compatibility which is the same as NULL but please use NULL)")
nomatch=NA # convert NA_character_ to NA-logical, PR#5216
}
if (!is.logical(which) || length(which)>1L) stopf("which= must be a logical vector length 1. Either FALSE, TRUE or NA.")
if ((isTRUE(which)||is.na(which)) && !missing(j)) stopf("which==%s (meaning return row numbers) but j is also supplied. Either you need row numbers or the result of j, but only one type of result can be returned.", which)
if (is.null(nomatch) && is.na(which)) stopf("which=NA with nomatch=0|NULL would always return an empty vector. Please change or remove either which or nomatch.")
if (!with && missing(j)) stopf("j must be provided when with=FALSE")
if (!missing(by) && !isTRUEorFALSE(showProgress)) stopf("%s must be TRUE or FALSE", "showProgress")
irows = NULL # Meaning all rows. We avoid creating 1:nrow(x) for efficiency.
notjoin = FALSE
rightcols = leftcols = integer()
optimizedSubset = FALSE ## flag: tells whether a normal query was optimized into a join.
..syms = NULL
av = NULL
jsub = NULL
if (!missing(j)) {
if (is.null(env)) jsub = substitute(j) else {
jsub = eval(substitute(
substitute2(.j, env),
list(.j = substitute(j))
))
if (missing(jsub)) {j = substitute(); jsub=NULL} else if (verbose && !is.null(env)) catf("Argument '%s' after substitute: %s\n", "j", paste(deparse(jsub, width.cutoff=500L), collapse=" "))
}
}
if (!missing(j)) {
jsub = replace_dot_alias(jsub)
root = root_name(jsub)
av = all.vars(jsub)
all..names = FALSE
if ((.is_withFALSE_range(jsub, x, root, av)) ||
(root %chin% c("-","!") && jsub[[2L]] %iscall% '(' && jsub[[2L]][[2L]] %iscall% ':') || ## x[, !(V8:V10)]
( (!length(av) || (all..names <- all(startsWith(av, "..")))) && ## x[, "V1"]; x[, ..v]
root %chin% c("","c","paste","paste0","-","!") && ## x[, c("V1","V2")]; x[, paste("V",1:2,sep="")]; x[, paste0("V",1:2)]
missingby )) { # test 763. TODO: likely that !missingby iff with==TRUE (so, with can be removed)
# When no variable names (i.e. symbols) occur in j, scope doesn't matter because there are no symbols to find.
# If variable names do occur, but they are all prefixed with .., then that means look up in calling scope.
# Automatically set with=FALSE in this case so that DT[,1], DT[,2:3], DT[,"someCol"] and DT[,c("colB","colD")]
# work as expected. As before, a vector will never be returned, but a single column data.table
# for type consistency with >1 cases. To return a single vector use DT[["someCol"]] or DT[[3]].
# The root==":" is to allow DT[,colC:colH] even though that contains two variable names.
# root == "-" or "!" is for tests 1504.11 and 1504.13 (a : with a ! or - modifier root)
# We don't want to evaluate j at all in making this decision because i) evaluating could itself
# increment some variable and not intended to be evaluated a 2nd time later on and ii) we don't
# want decisions like this to depend on the data or vector lengths since that can introduce
# inconsistency reminiscent of drop=TRUE in [.data.frame that we seek to avoid.
with=FALSE
if (all..names) {
for (..name in av) {
name = substr(..name, 3L, nchar(..name))
if (!nzchar(name)) stopf("The symbol .. is invalid. The .. prefix must be followed by at least one character.")
parent_has_..name = exists(..name, where=parent.frame())
if (!exists(name, where=parent.frame())) {
suggested = if (parent_has_..name)
gettextf(" Variable '..%s' does exist in calling scope though, so please just removed the .. prefix from that variable name in calling scope.", name)
# We have recommended 'manual' .. prefix in the past, so try to be helpful
else
""
stopf("Variable '%s' is not found in calling scope. Looking in calling scope because you used the .. prefix.%s", name, suggested)
} else if (parent_has_..name) {
warningf("Both '%1$s' and '..%1$s' exist in calling scope. Please remove the '..%1$s' variable in calling scope for clarity.", name)
}
}
..syms = av
}
} else if (is.name(jsub)) {
if (startsWith(as.character(jsub), "..")) internal_error("DT[, ..var] should be dealt with by the branch above now.") # nocov
if (!with && !exists(as.character(jsub), where=parent.frame()))
stopf("Variable '%s' is not found in calling scope. Looking in calling scope because you set with=FALSE. Also, please use .. symbol prefix and remove with=FALSE.", as.character(jsub))
}
if (root=="{") {
if (length(jsub) == 2L) {
jsub = jsub[[2L]] # to allow {} wrapping of := e.g. [,{`:=`(...)},] [#376]
root = root_name(jsub)
} else if (length(jsub) > 2L && jsub[[2L]] %iscall% ":=") {
#2142 -- j can be {} and have length 1
stopf("You have wrapped := with {} which is ok but then := must be the only thing inside {}. You have something else inside {} as well. Consider placing the {} on the RHS of := instead; e.g. DT[,someCol:={tmpVar1<-...;tmpVar2<-...;tmpVar1*tmpVar2}")
}
}
if (root=="eval" && !any(all.vars(jsub[[2L]]) %chin% names_x)) {
# TODO: this && !any depends on data. Can we remove it?
# Grab the dynamic expression from calling scope now to give the optimizer a chance to optimize it
# Only when top level is eval call. Not nested like x:=eval(...) or `:=`(x=eval(...), y=eval(...))
jsub = eval(jsub[[2L]], parent.frame(), parent.frame()) # this evals the symbol to return the dynamic expression
if (is.expression(jsub)) jsub = jsub[[1L]] # if expression, convert it to call
# Note that the dynamic expression could now be := (new in v1.9.7)
jsub = replace_dot_alias(jsub)
root = root_name(jsub)
}
if (root == ":=" || root == "let") { # let(...) as alias for :=(...) (#3795)
if (root == "let")
jsub[[1L]] = as.symbol(":=")
allow.cartesian=TRUE # (see #800)
if (!missing(i) && keyby)
stopf(":= with keyby is only possible when i is not supplied since you can't setkey on a subset of rows. Either change keyby to by or remove i")
if (!missingnomatch) {
warningf("nomatch isn't relevant together with :=, ignoring nomatch")
nomatch=NULL
}
}
}
# setdiff removes duplicate entries, which'll create issues with duplicated names. Use %chin% instead.
dupdiff = function(x, y) x[!x %chin% y]
isub = NULL
if (!missing(i)) {
if (is.null(env)) isub = substitute(i) else {
isub = eval(substitute(
substitute2(.i, env),
list(.i = substitute(i))
))
if (missing(isub)) {i = substitute(); isub=NULL} else if (verbose && !is.null(env)) catf("Argument '%s' after substitute: %s\n", "i", paste(deparse(isub, width.cutoff=500L), collapse=" "))
}
}
if (!missing(i)) {
xo = NULL
if (identical(isub, NA)) {
# only possibility *isub* can be NA (logical) is the symbol NA itself; i.e. DT[NA]
# replace NA in this case with NA_integer_ as that's almost surely what user intended to
# return a single row with NA in all columns. (DT[0] returns an empty table, with correct types.)
# Any expression (including length 1 vectors) that evaluates to a single NA logical will
# however be left as NA logical since that's important for consistency to return empty in that
# case; e.g. DT[Col==3] where DT is 1 row and Col contains NA.
# Replacing the NA symbol makes DT[NA] and DT[c(1,NA)] consistent and provides
# an easy way to achieve a single row of NA as users expect rather than requiring them
# to know and change to DT[NA_integer_].
isub=NA_integer_
}
isnull_inames = FALSE
# Fixes 4994: a case where quoted expression with a "!", ex: expr = quote(!dt1); dt[eval(expr)] requires
# the "eval" to be checked before `as.name("!")`. Therefore interchanged.
restore.N = remove.N = FALSE
old.N = get0(".N", envir=parent.frame(), inherits=FALSE)
if (!is.null(old.N)) {
locked.N = bindingIsLocked(".N", parent.frame())
if (locked.N) eval(call("unlockBinding", ".N", parent.frame())) # eval call to pass R CMD check NOTE until we find cleaner way
assign(".N", nrow(x), envir=parent.frame(), inherits=FALSE)
restore.N = TRUE
# the comment below is invalid hereafter (due to fix for #1145)
# binding locked when .SD[.N] but that's ok as that's the .N we want anyway
# TO DO: change isub at C level s/.N/nrow(x); changing a symbol to a constant should be ok
} else {
assign(".N", nrow(x), envir=parent.frame(), inherits=FALSE)
remove.N = TRUE
}
if (isub %iscall% "eval") { # TO DO: or ..()
isub = eval(.massagei(isub[[2L]]), parent.frame(), parent.frame())
if (is.expression(isub)) isub=isub[[1L]]
}
if (isub %iscall% "!") {
notjoin = TRUE
if (!missingnomatch) stopf("not-join '!' prefix is present on i but nomatch is provided. Please remove nomatch.");
nomatch = NULL
isub = isub[[2L]]
# #932 related so that !(v1 == 1) becomes v1 == 1 instead of (v1 == 1) after removing "!"
if (isub %iscall% "(" && !is.name(isub[[2L]]))
isub = isub[[2L]]
}
if (is.null(isub)) return( null.data.table() )
if (length(o <- .prepareFastSubset(isub = isub, x = x,
enclos = parent.frame(),
notjoin = notjoin, verbose = verbose))){
## redirect to the is.data.table(x) == TRUE branch.
## Additional flag to adapt things after bmerge:
optimizedSubset = TRUE
notjoin = o$notjoin
i = o$i
on = o$on
## the following two are ignored if i is not a data.table.
## Since we are converting i to data.table, it is important to set them properly.
nomatch = NULL
mult = "all"
}
else if (!is.name(isub)) {
ienv = new.env(parent=parent.frame())
if (getOption("datatable.optimize") >= 1L) assign("order", forder, ienv)
i = tryCatch(eval(.massagei(isub), x, ienv),
dt_invalid_let_error = function(e) stopf("Operator := detected in i, the first argument inside DT[...], but is only valid in the second argument, j. Most often, this happens when forgetting the first comma (e.g. DT[newvar := 5] instead of DT[ , new_var := 5]). Please double-check the syntax. Run traceback(), and debugger() to get a line number."),
error = function(e) .checkTypos(e, names_x)
)
} else {
# isub is a single symbol name such as B in DT[B]
i = try(eval(isub, parent.frame(), parent.frame()), silent=TRUE)
if (inherits(i,"try-error") || is.function(i)) {
# must be "not found" since isub is a mere symbol
col = try(eval(isub, x), silent=TRUE) # is it a column name?
msg = if (inherits(col, "try-error")) gettextf(
"'%s' is not found in calling scope and it is not a column name either",
as.character(isub)
) else gettextf(
"'%s' is not found in calling scope, but it is a column of type %s. If you wish to select rows where that column contains TRUE, or perhaps that column contains row numbers of itself to select, try DT[(col)], DT[DT$col], or DT[col==TRUE} is particularly clear and is optimized",
as.character(isub), typeof(col)
)
stopf("%s. When the first argument inside DT[...] is a single symbol (e.g. DT[var]), data.table looks for var in calling scope.", msg)
}
}
if (restore.N) {
assign(".N", old.N, envir=parent.frame())
if (locked.N) lockBinding(".N", parent.frame())
}
if (remove.N) rm(list=".N", envir=parent.frame())
if (is.matrix(i)) {
if (is.numeric(i) && ncol(i)==1L) { # #826 - subset DT on single integer vector stored as matrix
i = as.integer(i)
} else {
stopf("i is invalid type (matrix). Perhaps in future a 2 column matrix could return a list of elements of DT (in the spirit of A[B] in FAQ 2.14). Please report to data.table issue tracker if you'd like this, or add your comments to FR #657.")
}
}
if (is.logical(i)) {
if (notjoin) {
notjoin = FALSE
i = !i
}
}
if (is.null(i)) return( null.data.table() )
if (is.character(i) || is.factor(i)) {
isnull_inames = TRUE
i = data.table(V1=i) # for user convenience; e.g. DT["foo"] without needing DT[.("foo")]
} else if (identical(class(i),"list") && length(i)==1L && is.data.frame(i[[1L]])) { i = as.data.table(i[[1L]]) }
else if (identical(class(i),"data.frame")) { i = as.data.table(i) } # TO DO: avoid these as.data.table() and use a flag instead
else if (identical(class(i),"list")) {
isnull_inames = is.null(names(i))
i = as.data.table(i)
}
if (is.data.frame(i)) {
if (missing(on)) {
if (!haskey(x)) {
stopf("When i is a data.table (or character vector), the columns to join by must be specified using 'on=' argument (see ?data.table), by keying x (i.e. sorted, and, marked as sorted, see ?setkey), or by sharing column names between x and i (i.e., a natural join). Keyed joins might have further speed benefits on very large data due to x being sorted in RAM.")
}
} else if (identical(substitute(on), as.name(".NATURAL"))) {
naturaljoin = TRUE
}
if (naturaljoin) { # natural join #629
common_names = intersect(names_x, names(i))
len_common_names = length(common_names)
if (!len_common_names) stopf("Attempting to do natural join but no common columns in provided tables")
if (verbose) {
which_cols_msg = if (len_common_names == length(x)) {
catf("Joining but 'x' has no key, natural join using all 'x' columns")
} else {
catf("Joining but 'x' has no key, natural join using: %s", brackify(common_names))
}
}
on = common_names
}
if (!missing(on)) {
# on = .() is now possible, #1257
on_ops = .parse_on(substitute(on), isnull_inames)
on = on_ops[[1L]]
ops = on_ops[[2L]]
if (any(ops > 1L)) { ## fix for #4489; ops = c("==", "<=", "<", ">=", ">", "!=")
allow.cartesian = TRUE
}
# TODO: collect all '==' ops first to speeden up Cnestedid
rightcols = colnamesInt(x, names(on), check_dups=FALSE)
leftcols = colnamesInt(i, unname(on), check_dups=FALSE)
} else {
## missing on
rightcols = chmatch(key(x), names_x) # NAs here (i.e. invalid data.table) checked in bmerge()
leftcols = if (haskey(i))
chmatch(head(key(i), length(rightcols)), names(i))
else
seq_len(min(length(i),length(rightcols)))
rightcols = head(rightcols,length(leftcols))
ops = rep(1L, length(leftcols))
}
# Implementation for not-join along with by=.EACHI, #604
if (notjoin && (byjoin || mult != "all")) { # mult != "all" needed for #1571
notjoin = FALSE
if (verbose) {last.started.at=proc.time();catf("not-join called with 'by=.EACHI'; Replacing !i with i=setdiff_(x,i) ...");flush.console()}
orignames = copy(names(i))
i = setdiff_(x, i, rightcols, leftcols) # part of #547
if (verbose) {catf("done in %s\n",timetaken(last.started.at)); flush.console()}
setnames(i, orignames[leftcols])
setattr(i, 'sorted', names(i)) # since 'x' has key set, this'll always be sorted
}
i = .shallow(i, retain.key = TRUE)
ans = bmerge(i, x, leftcols, rightcols, roll, rollends, nomatch, mult, ops, verbose=verbose)
xo = ans$xo ## to make it available for further use.
# temp fix for issue spotted by Jan, test #1653.1. TODO: avoid this
# 'setorder', as there's another 'setorder' in generating 'irows' below...
if (length(ans$indices)) setorder(setDT(ans[1L:3L]), indices)
allLen1 = ans$allLen1
f__ = ans$starts
len__ = ans$lens
allGrp1 = all(ops==1L) # was previously 'ans$allGrp1'. Fixing #1991. TODO: Revisit about allGrp1 possibility for speedups in certain cases when I find some time.
indices__ = if (length(ans$indices)) ans$indices else seq_along(f__) # also for #1991 fix
# When no match, len__ is 0 for nomatch=NULL and 1 for nomatch=NA, so len__ isn't .N
# If using secondary key of x, f__ will refer to xo
if (is.na(which)) {
w = if (notjoin) f__!=0L else is.na(f__)
return( if (length(xo)) fsort(xo[w], internal=TRUE) else which(w) )
}
if (mult=="all") {
# is by=.EACHI along with non-equi join?
nqbyjoin = byjoin && length(ans$indices) && !allGrp1
if (!byjoin || nqbyjoin) {
# Really, `anyDuplicated` in base is AWESOME!
# allow.cartesian shouldn't error if a) not-join, b) 'i' has no duplicates
if (verbose) {last.started.at=proc.time();catf("Constructing irows for '!byjoin || nqbyjoin' ... ");flush.console()}
irows = if (allLen1) f__ else vecseq(f__,len__,
if (allow.cartesian ||
notjoin || # #698. When notjoin=TRUE, ignore allow.cartesian. Rows in answer will never be > nrow(x).
!anyDuplicated(f__, incomparables = c(0L, NA_integer_))) {
NULL # #742. If 'i' has no duplicates, ignore
} else as.double(nrow(x)+nrow(i))) # rows in i might not match to x so old max(nrow(x),nrow(i)) wasn't enough. But this limit now only applies when there are duplicates present so the reason now for nrow(x)+nrow(i) is just to nail it down and be bigger than max(nrow(x),nrow(i)).
if (verbose) {cat(timetaken(last.started.at),"\n"); flush.console()}
# Fix for #1092 and #1074
# TODO: implement better version of "any"/"all"/"which" to avoid
# unnecessary construction of logical vectors
if (is.null(nomatch) && allLen1) irows = irows[irows != 0L]
} else {
if (length(xo) && missing(on))
internal_error("Cannot by=.EACHI when joining to an index, yet") # nocov
# since f__ refers to xo later in grouping, so xo needs to be passed through to dogroups too.
if (length(irows))
internal_error("irows has length in by=.EACHI") # nocov
}
if (nqbyjoin) {
irows = if (length(xo)) xo[irows] else irows
xo = setorder(setDT(list(indices=rep.int(indices__, len__), irows=irows)))[["irows"]]
ans = .Call(CnqRecreateIndices, xo, len__, indices__, max(indices__), nomatch) # issue#4388 fix
f__ = ans[[1L]]; len__ = ans[[2L]]
allLen1 = FALSE # TODO; should this always be FALSE?
irows = NULL # important to reset
if (any_na(as_list(xo))) xo = xo[!is.na(xo)]
}
} else {
if (!byjoin) { #1287 and #1271
irows = f__ # len__ is set to 1 as well, no need for 'pmin' logic
if (is.null(nomatch)) irows = irows[len__>0L] # 0s are len 0, so this removes -1 irows
}
# TODO: when nomatch=NA, len__ need not be allocated / set at all for mult="first"/"last"?
# TODO: how about when nomatch=NULL, can we avoid allocating then as well?
}
if (length(xo) && length(irows)) {
irows = xo[irows] # TO DO: fsort here?
if (mult=="all" && !allGrp1) { # following #1991 fix, !allGrp1 will always be TRUE. TODO: revisit.
if (verbose) {last.started.at=proc.time();catf("Reorder irows for 'mult==\"all\" && !allGrp1' ... ");flush.console()}
irows = setorder(setDT(list(indices=rep.int(indices__, len__), irows=irows)))[["irows"]]
if (verbose) {cat(timetaken(last.started.at),"\n"); flush.console()}
}
}
if (optimizedSubset){
## special treatment for calls like DT[x == 3] that are transformed into DT[J(x=3), on = "x==x"]
if(!.Call(CisOrderedSubset, irows, nrow(x))){
## restore original order. This is a very expensive operation.
## benchmarks have shown that starting with 1e6 irows, a tweak can significantly reduce time
## (see #2366)
if (verbose) {last.started.at=proc.time();catf("Reordering %d rows after bmerge done in ... ", length(irows));flush.console()}
if(length(irows) < 1e6){
irows = fsort(irows, internal=TRUE) ## internally, fsort on integer falls back to forderv
} else {
irows = as.integer(fsort(as.numeric(irows))) ## nocov; parallelized for numeric, but overhead of type conversion
}
if (verbose) {cat(timetaken(last.started.at), "\n");flush.console()}
}
## make sure, all columns are taken from x and not from i.
## This is done by simply telling data.table to continue as if there was a simple subset
leftcols = integer(0L)
rightcols = integer(0L)
i = irows ## important to make i not a data.table because otherwise Gforce doesn't kick in
}
}
else {
if (!missing(on)) {
stopf("logical error. i is not a data.table, but 'on' argument is provided.")
}
# TO DO: TODO: Incorporate which_ here on DT[!i] where i is logical. Should avoid i = !i (above) - inefficient.
# i is not a data.table
if (!is.logical(i) && !is.numeric(i)) stopf("i has evaluated to type %s. Expecting logical, integer or double.", typeof(i))
if (is.logical(i)) {
if (is.na(which)) { # #4411 i filter not optimized to join: DT[A > 1, which = NA]
## we need this branch here, not below next to which=TRUE because irows=i=which(i) will filter out NAs: DT[A > 10, which = NA] will be incorrect
if (notjoin) internal_error("notjoin and which=NA (non-matches), huh") # nocov
return(which(is.na(i) | !i))
}
if (length(i)==1L # to avoid unname copy when length(i)==nrow (normal case we don't want to slow down)
&& isTRUE(unname(i))) { irows=i=NULL } # unname() for #2152 - length 1 named logical vector.
# NULL is efficient signal to avoid creating 1:nrow(x) but still return all rows, fixes #1249
else if (length(i)<=1L) { irows=i=integer(0L) }
# FALSE, NA and empty. All should return empty data.table. The NA here will be result of expression,
# where for consistency of edge case #1252 all NA to be removed. If NA is a single NA symbol, it
# was auto converted to NA_integer_ higher up for ease of use and convenience. We definitely
# don't want base R behaviour where DF[NA,] returns an entire copy filled with NA everywhere.
else if (length(i)==nrow(x)) { irows=i=which(i) }
# The which() here auto removes NA for convenience so user doesn't need to remember "!is.na() & ..."
# Also this which() is for consistency of DT[colA>3,which=TRUE] and which(DT[,colA>3])
# Assigning to 'i' here as well to save memory, #926.
else stopf("i evaluates to a logical vector length %d but there are %d rows. Recycling of logical i is no longer allowed as it hides more bugs than is worth the rare convenience. Explicitly use rep(...,length=.N) if you really need to recycle.", length(i), nrow(x))
} else {
irows = as.integer(i) # e.g. DT[c(1,3)] and DT[c(-1,-3)] ok but not DT[c(1,-3)] (caught as error)
if (nomatch0) warningf("Please use nomatch=NULL instead of nomatch=0; see news item 5 in v1.12.0 (Jan 2019)")
# warning only for this case where nomatch was ignored before v1.14.2; #3109
irows = .Call(CconvertNegAndZeroIdx, irows, nrow(x),
is.null(jsub) || root!=":=", # allowOverMax (NA when selecting, error when assigning)
!is.null(nomatch)) # allowNA=false when nomatch=NULL #3109, true when nomatch=NA #3666
# simplifies logic from here on: can assume positive subscripts (no zeros), for nomatch=NULL also no NAs
# maintains Arun's fix for #2697 (test 1042)
# efficient in C with more detailed helpful messages when user mixes positives and negatives
# falls through quickly (no R level allocs) if all items are within range [1,max] with no zeros or negatives
# minor TO DO: can we merge this with check_idx in fcast.c/subset ?
}
}
if (notjoin) {
if (byjoin || !is.integer(irows) || !is.null(nomatch)) internal_error("notjoin but byjoin or !integer or nomatch==NA") # nocov
irows = irows[irows!=0L]
if (verbose) {last.started.at=proc.time();catf("Inverting irows for notjoin done in ... ");flush.console()}
i = irows = if (length(irows)) seq_len(nrow(x))[-irows] else NULL # NULL meaning all rows i.e. seq_len(nrow(x))
if (verbose) cat(timetaken(last.started.at), "\n")
leftcols = integer() # proceed as if row subset from now on, length(leftcols) is switched on later
rightcols = integer()
# Doing this once here, helps speed later when repeatedly subsetting each column. R's [irows] would do this for each
# column when irows contains negatives.
}
if (which) return( if (is.null(irows)) seq_len(nrow(x)) else irows )
} else { # missing(i)
i = NULL
}
names_i = names(i) # value is now stable
byval = NULL
xnrow = nrow(x)
xcols = xcolsAns = icols = icolsAns = integer()
xdotcols = FALSE
# track which columns appear in j through ansvars, and those
# that belong in .SD through sdvars. Mostly these will be the same,
# except in cases like DT[ , lapply(.SD, function(x) x/V1), .SDcols = !'V1'],
# see e.g. #484, #495, #1744, #1965.
non_sdvars = character(0L)
if (missing(j)) {
# missingby was already checked above before dealing with i
if (!length(x)) return(null.data.table())
if (!length(leftcols)) {
# basic x[i] subset, #2951
if (is.null(irows)) return(shallow(x)) # e.g. DT[TRUE] (#3214); otherwise CsubsetDT would materialize a deep copy
else return(.Call(CsubsetDT, x, irows, seq_along(x)) )
} else {
jisvars = names_i[-leftcols]
tt = jisvars %chin% names_x
if (length(tt)) jisvars[tt] = paste0("i.",jisvars[tt])
if (length(duprightcols <- rightcols[duplicated(rightcols)])) {
nx = c(names_x, names_x[duprightcols])
rightcols = chmatchdup(names_x[rightcols], nx)
nx = make.unique(nx)
} else nx = names_x
ansvars = make.unique(c(nx, jisvars))
icols = c(leftcols, seq_along(i)[-leftcols])
icolsAns = c(rightcols, seq.int(length(nx)+1L, length.out=ncol(i)-length(unique(leftcols))))
xcols = xcolsAns = seq_along(x)[-rightcols]
}
ansvals = chmatch(ansvars, nx)
} else {
if (is.data.table(i)) {
idotprefix = paste0("i.", names_i)
xdotprefix = paste0("x.", names_x)
} else idotprefix = xdotprefix = character(0L)
# j was substituted before dealing with i so that := can set allow.cartesian=FALSE (#800) (used above in i logic)
if (is.null(jsub)) return(NULL)
if (!with && jsub %iscall% ":=") {
# TODO: make these both errors (or single long error in both cases) in next release.
# i.e. using with=FALSE together with := at all will become an error. Eventually with will be removed.
if (is.null(names(jsub)) && is.name(jsub[[2L]])) {
warningf("with=FALSE together with := was deprecated in v1.9.4 released Oct 2014. Please wrap the LHS of := with parentheses; e.g., DT[,(myVar):=sum(b),by=a] to assign to column name(s) held in variable myVar. See ?':=' for other examples. As warned in 2014, this is now a warning.")
jsub[[2L]] = eval(jsub[[2L]], parent.frame(), parent.frame())
} else {
warningf("with=FALSE ignored, it isn't needed when using :=. See ?':=' for examples.")
}
with = TRUE
}
if (!with) {
# missingby was already checked above before dealing with i
if (jsub %iscall% c("!", "-") && length(jsub)==2L) { # length 2 to only match unary, #2109
notj = TRUE
jsub = jsub[[2L]]
} else notj = FALSE
# fix for #1216, make sure the parentheses are peeled from expr of the form (((1:4)))
while (jsub %iscall% "(") jsub = as.list(jsub)[[-1L]]
if (jsub %iscall% ":" && length(jsub)==3L) {
j = eval(jsub, setattr(as.list(seq_along(x)), 'names', names_x), parent.frame()) # else j will be evaluated for the first time on next line
} else {
names(..syms) = ..syms
j = eval(jsub, lapply(substr(..syms, 3L, nchar(..syms)), get, pos=parent.frame()), parent.frame())
}
if (is.logical(j)) j <- which(j)
if (!length(j) && !notj) return( null.data.table() )
if (is.factor(j)) j = as.character(j) # fix for FR: #358
if (is.character(j)) {
if (notj) {
if (anyNA(idx <- chmatch(j, names_x)))
warningf(ngettext(sum(is.na(idx)), "column not removed because not found: %s", "columns not removed because not found: %s"),
brackify(j[is.na(idx)]), domain=NA)
# all duplicates of the name in names(x) must be removed; e.g. data.table(x=1, y=2, x=3)[, !"x"] should just output 'y'.
w = !names_x %chin% j
ansvars = names_x[w]
ansvals = which(w)
} else {
# if DT[, c("x","x")] and "x" is duplicated in names(DT), we still subset only the first. Because dups are unusual and
# it's more common to select the same column a few times. A syntax would be needed to distinguish these intents.
ansvars = j # x. and i. prefixes may be in here, they'll result in NA and will be dealt with further below if length(leftcols)
ansvals = chmatch(ansvars, names_x) # not chmatchdup()
}
if (!length(ansvals)) return(null.data.table())
if (!length(leftcols)) {
if (!anyNA(ansvals)) return(.Call(CsubsetDT, x, irows, ansvals))
else stopf(ngettext(sum(is.na(ansvals)), "column not found: %s", "columns not found: %s"),
brackify(ansvars[is.na(ansvals)]), domain=NA)
}
# else the NA in ansvals are for join inherited scope (test 1973), and NA could be in irows from join and data in i should be returned (test 1977)
# in both cases leave to the R-level subsetting of i and x together further below
} else if (is.numeric(j)) {
j = as.integer(j)
if (any(w <- (j>ncol(x)))) stopf("Item %d of j is %d which is outside the column number range [1,ncol=%d]", idx <- which.first(w), j[idx], ncol(x))
j = j[j!=0L]
if (any(j<0L)) {
if (any(j>0L)) stopf("j mixes positives and negatives")
j = seq_along(x)[j] # all j are <0 here
}
# 3013 -- handle !FALSE in column subset in j via logical+with
if (notj) j = seq_along(x)[if (length(j)) -j else TRUE]
if (!length(j)) return(null.data.table())
return(.Call(CsubsetDT, x, irows, j))
} else {
stopf("When with=FALSE, j-argument should be of type logical/character/integer indicating the columns to select.") # fix for #1440.
}
} else { # with=TRUE and byjoin could be TRUE
bynames = NULL
allbyvars = NULL
if (byjoin) {
bynames = names_x[rightcols]
} else if (!missingby) {
# deal with by before j because we need byvars when j contains .SD
# may evaluate to NULL | character() | "" | list(), likely a result of a user expression where no-grouping is one case being loop'd through
bysubl = as.list.default(bysub)
bysuborig = bysub
if (".I" %in% bysubl) { #1732
if (!is.symbol(bysub) && (length(bysubl)!=2L || !is.symbol(bysubl[[2L]]) || !(bysubl[[1L]] %chin% c(".","c","list"))))
stopf("'by' contains .I but only the following are currently supported: by=.I, by=.(.I), by=c(.I), by=list(.I)")
bysub = if (is.null(irows)) seq_len(nrow(x)) else irows
bysuborig = as.symbol("I")
}
if (is.name(bysub) && !(bysub %chin% names_x)) { # TO DO: names(x),names(i),and i. and x. prefixes
bysub = eval(bysub, parent.frame(), parent.frame())
# fix for # 5106 - http://stackoverflow.com/questions/19983423/why-by-on-a-vector-not-from-a-data-table-column-is-very-slow
# case where by=y where y is not a column name, and not a call/symbol/expression, but an atomic vector outside of DT.
# note that if y is a list, this'll return an error (not sure if it should).
if (is.atomic(bysub)) bysubl = list(bysuborig) else bysubl = as.list.default(bysub)
}
if (length(bysubl) && identical(bysubl[[1L]],quote(eval))) { # TO DO: or by=..()
bysub = eval(bysubl[[2L]], parent.frame(), parent.frame())
bysub = replace_dot_alias(bysub) # fix for #1298
if (is.expression(bysub)) bysub=bysub[[1L]]
bysubl = as.list.default(bysub)
} else if (bysub %iscall% c("c","key","names", "intersect", "setdiff")) {
# catch common cases, so we don't have to copy x[irows] for all columns
# *** TO DO ***: try() this eval first (as long as not list() or .()) and see if it evaluates to column names
# to avoid the explicit c,key,names which already misses paste("V",1:10) for example
# tried before but since not wrapped in try() it failed on some tests
# or look for column names used in this by (since if none it wouldn't find column names anyway
# when evaled within full x[irows]). Trouble is that colA%%2L is a call and should be within frame.
tt = eval(bysub, parent.frame(), parent.frame())
if (!is.character(tt)) stopf("by=c(...), key(...) or names(...) must evaluate to 'character'")
bysub=tt
} else if (is.call(bysub) && !(bysub[[1L]] %chin% c("list", "as.list", "{", ".", ":"))) {
# potential use of function, ex: by=month(date). catch it and wrap with "(", because we need to set "bysameorder" to FALSE as we don't know if the function will return ordered results just because "date" is ordered. Fixes #2670.
bysub = as.call(c(as.name('('), list(bysub)))
bysubl = as.list.default(bysub)
} else if (bysub %iscall% ".") bysub[[1L]] = quote(list)
if (mode(bysub) == "character") {
if (any(grepl(",", bysub, fixed = TRUE))) {
if (length(bysub) > 1L) stopf("'by' is a character vector length %d but one or more items include a comma. Either pass a vector of column names (which can contain spaces, but no commas), or pass a vector length 1 containing comma separated column names. See ?data.table for other possibilities.", length(bysub))
bysub = cols_from_csv(bysub)
}
bysub = gsub("^`(.*)`$", "\\1", bysub) # see test 138
nzidx = nzchar(bysub)
# by='' means by=NULL, tests 592&596
if (!all(nzidx)) {
if (length(bysub) > 1L) stopf("At least one entry of by is empty")
bysub = NULL
} else {
bysub = as.call(c(list(quote(list)), lapply(bysub, as.name)))
}
bysubl = as.list.default(bysub)
}
if (any(c("eval","evalq","eval.parent","local","get","mget","dynGet") %chin% all.names(bysub)))
# when the 'by' expression includes get/mget/eval, all.vars cannot be trusted to infer all used columns, #4981
allbyvars = NULL
else
allbyvars = intersect(all.vars(bysub), names_x)
orderedirows = .Call(CisOrderedSubset, irows, nrow(x)) # TRUE when irows is NULL (i.e. no i clause). Similar but better than is.sorted(f__)
bysameorder = byindex = FALSE
if (!bysub %iscall% ":" && ##Fix #4285
all(vapply_1b(bysubl, is.name))) {
bysameorder = orderedirows && haskey(x) && length(allbyvars) && identical(allbyvars,head(key(x),length(allbyvars)))
# either bysameorder or byindex can be true but not both. TODO: better name for bysameorder might be bykeyx
if (!bysameorder && keyby && !length(irows) && isTRUE(getOption("datatable.use.index"))) {
# TODO: could be allowed if length(irows)>1 but then the index would need to be squashed for use by uniqlist, #3062
# find if allbyvars is leading subset of any of the indices; add a trailing "__" to fix #3498 where a longer column name starts with a shorter column name
tt = paste(c(allbyvars,""), collapse="__")
w = which.first(startsWith(paste0(indices(x), "__"), tt))
if (!is.na(w)) {
byindex = indices(x)[w]
if (!length(getindex(x, byindex))) {
if (verbose) catf("by index '%s' but that index has 0 length. Ignoring.\n", byindex)
byindex=FALSE
}
}
}
}
if (is.null(irows)) {
if (bysub %iscall% ':' && length(bysub)==3L && is.name(bysub[[2L]]) && is.name(bysub[[3L]])) {
byval = eval(bysub, setattr(as.list(seq_along(x)), 'names', names_x), parent.frame())
byval = as.list(x)[byval]
} else byval = eval(bysub, x, parent.frame())
} else {
# length 0 when i returns no rows
if (!is.integer(irows)) internal_error("irows isn't integer") # nocov
# Passing irows as i to x[] below has been troublesome in a rare edge case.
# irows may contain NA, 0, negatives and >nrow(x) here. That's all ok.
# But we may need i join column values to be retained (where those rows have no match), hence we tried eval(isub)
# in 1.8.3, but this failed test 876.
# TO DO: Add a test like X[i,sum(v),by=i.x2], or where by includes a join column (both where some i don't match).
# TO DO: Make xss directly, rather than recursive call.
if (is.null(nomatch)) irows = irows[irows!=0L] # TO DO: can be removed now we have CisSortedSubset
if (length(allbyvars)) { ############### TO DO TO DO TO DO ###############
if (verbose) catf("i clause present and columns used in by detected, only these subset: %s\n", brackify(allbyvars))
xss = `[.data.table`(x,irows,allbyvars,with=FALSE,nomatch=nomatch,mult=mult,roll=roll,rollends=rollends)
} else {
if (verbose) catf("i clause present but columns used in by not detected. Having to subset all columns before evaluating 'by': '%s'\n", deparse(by))
xss = `[.data.table`(x,irows,nomatch=nomatch,mult=mult,roll=roll,rollends=rollends)
}
if (bysub %iscall% ':' && length(bysub)==3L) {
byval = eval(bysub, setattr(as.list(seq_along(xss)), 'names', names(xss)), parent.frame())
byval = as.list(xss)[byval]
} else byval = eval(bysub, xss, parent.frame())
xnrow = nrow(xss)
# TO DO: pass xss (x subset) through into dogroups. Still need irows there (for :=), but more condense
# and contiguous to use xss to form .SD in dogroups than going via irows
}
if (!length(byval) && xnrow>0L) {
# see missingby up above for comments
# by could be NULL or character(0L) for example (e.g. passed in as argument in a loop of different bys)
bysameorder = FALSE # 1st and only group is the entire table, so could be TRUE, but FALSE to avoid
# a key of empty character()
byval = list()
bynames = allbyvars = NULL
# the rest now fall through
} else bynames = names(byval)
if (is.atomic(byval) || is.null(byval)) {
if (is.character(byval) && length(byval)<=ncol(x) && !(is.name(bysub) && bysub %chin% names_x) ) {
stopf("'by' appears to evaluate to column names but isn't c() or key(). Use by=list(...) if you can. Otherwise, by=eval%s should work. This is for efficiency so data.table can detect which columns are needed.", deparse(bysub))
} else {
# by may be a single unquoted column name but it must evaluate to list so this is a convenience to users. Could also be a single expression here such as DT[,sum(v),by=colA%%2]
byval = list(byval)
bysubl = c(as.name("list"),bysuborig) # for guessing the column name below
if (is.name(bysuborig))
bynames = as.character(bysuborig)
else
bynames = names(byval)
}
}
if (!is.list(byval)) stopf("'by' or 'keyby' must evaluate to a vector or a list of vectors (where 'list' includes data.table and data.frame which are lists, too)")
if (length(byval)==1L && is.null(byval[[1L]])) bynull=TRUE #3530 when by=(function()NULL)()
if (!bynull) for (jj in seq_along(byval)) {
if (!(this_type <- typeof(byval[[jj]])) %chin% ORDERING_TYPES) {
stopf("Column or expression %d of 'by' or 'keyby' is type '%s' which is not currently supported. If you have a compelling use case, please add it to https://github.com/Rdatatable/data.table/issues/1597. As a workaround, consider converting the column to a supported type, e.g. by=sapply(list_col, toString), whilst taking care to maintain distinctness in the process.", jj, this_type)
}
}
tt = lengths(byval)
if (any(tt!=xnrow)) {
plural_part <- sprintf(ngettext(length(tt), "The item in the 'by' or 'keyby' list is length %s.", "The items in the 'by' or 'keyby' list have lengths %s."), brackify(tt))
stopf("%s Each must be length %d; the same length as there are rows in x (after subsetting if i is provided).", plural_part, xnrow)
}
if (is.null(bynames)) bynames = rep.int("",length(byval))
if (length(idx <- which(!nzchar(bynames))) && !bynull) {
# TODO: improve this and unify auto-naming of jsub and bysub
if (is.name(bysubl[[1L]]) && bysubl[[1L]] == '{') bysubl = bysubl[[length(bysubl)]] # fix for #3156
for (jj in idx) {
# Best guess. Use "month" in the case of by=month(date), use "a" in the case of by=a%%2
byvars = all.vars(bysubl[[jj+1L]], functions = TRUE)
if (length(byvars) == 1L) tt = byvars
else {
# take the first variable that is (1) not eval (#3758) and (2) starts with a character that can't start a variable name
tt = grep("^eval$|^[^[:alpha:]. ]", byvars, invert=TRUE, value=TRUE)
# byvars but exclude functions or `0`+`1` becomes `+`
tt = if (length(tt)) tt[1L] else all.vars(bysubl[[jj+1L]])[1L]
}
# fix for #497
if (length(byvars) > 1L && tt %chin% all.vars(jsub, FALSE)) {
bynames[jj] = deparse(bysubl[[jj+1L]])
if (verbose)
catf("by-expression '%s' is not named, and the auto-generated name '%s' clashed with variable(s) in j. Therefore assigning the entire by-expression as name.\n", bynames[jj], tt)
}
else bynames[jj] = tt
# if user doesn't like this inferred name, user has to use by=list() to name the column
}
# Fix for #1334
if (anyDuplicated(bynames)) {
bynames = make.unique(bynames)
}
}
setattr(byval, "names", bynames) # byval is just a list not a data.table hence setattr not setnames
}
jvnames = NULL
drop_dot = function(x) {
if (length(x)!=1L) internal_error("drop_dot passed %d items", length(x)) # nocov
if (startsWith(x<-as.character(x), ".") && x %chin% c(".N", ".I", ".GRP", ".NGRP", ".BY"))
substr(x, 2L, nchar(x))
else
x
}
# handle auto-naming of last item of j (e.g. within {} or if/else, #2478)
# e.g. DT[, .(a=sum(v), v, .N), by=] should create columns named a, v, N
do_j_names = function(q) {
if (!is.call(q) || !is.name(q[[1L]])) return(q)
if (q[[1L]] %chin% c('list', '.')) {
q[[1L]] = quote(list)
qlen = length(q)
if (qlen>1L) {
nm = names(q[-1L]) # check list(a=sum(v),v)
if (is.null(nm)) nm = rep.int("", qlen-1L)
# attempt to auto-name unnamed columns
for (jj in which(!nzchar(nm))) {
thisq = q[[jj + 1L]]
if (missing(thisq)) stopf("Item %d of the .() or list() passed to j is missing", jj) #3507
if (is.name(thisq)) nm[jj] = drop_dot(thisq)
# TO DO: if call to a[1] for example, then call it 'a' too
}
if (!is.null(jvnames)) {
if (length(nm) != length(jvnames))
warningf("j may not evaluate to the same number of columns for each group; if you're sure this warning is in error, please put the branching logic outside of [ for efficiency")
else if (any(idx <- nm != jvnames))
warningf('Different branches of j expression produced different auto-named columns: %s; using the most "last" names. If this was intentional (e.g., you know only one branch will ever be used in a given query because the branch is controlled by a function argument), please (1) pull this branch out of the call; (2) explicitly provide missing defaults for each branch in all cases; or (3) use the same name for each branch and re-name it in a follow-up call.', brackify(sprintf('%s!=%s', nm[idx], jvnames[idx])))
}
# nolint next: undesirable_operator_linter. Workaround is clunkier, though a bigger refactor could be considered.
jvnames <<- nm # TODO: handle if() list(a, b) else list(b, a) better
setattr(q, "names", NULL) # drops the names from the list so it's faster to eval the j for each group; reinstated at the end on the result.
}
return(q) # else empty list is needed for test 468: adding an empty list column
}
if (q[[1L]] == '{') {
if (!is.null(q[[qlen<-length(q)]])) q[[qlen]] = do_j_names(q[[qlen]])
return(q)
}
if (q[[1L]] == 'if') {
#explicit NULL would return NULL, assigning NULL would delete that from the expression
if (!is.null(q[[3L]])) q[[3L]] = do_j_names(q[[3L]])
if (length(q) == 4L && !is.null(q[[4L]])) q[[4L]] = do_j_names(q[[4L]])
return(q)
}
q
}
if (is.name(jsub)) {
# j is a single unquoted column name
if (jsub!=".SD") jvnames = drop_dot(jsub)
# jsub is list()ed after it's eval'd inside dogroups.
} else jsub = do_j_names(jsub) # else maybe a call to transform or something which returns a list.
av = all.vars(jsub,TRUE) # TRUE fixes bug #1294 which didn't see b in j=fns[[b]](c)
use.I = ".I" %chin% av
if (any(c(".SD","eval","get","mget") %chin% av)) {
if (missing(.SDcols)) {
# here we need to use 'dupdiff' instead of 'setdiff'. Ex: setdiff(c("x", "x"), NULL) will give 'x'.
# slight memory efficiency boost if we only store sdvars if it differs from ansvars, but a bit tricky to examine all the uses here
ansvars = sdvars = dupdiff(names_x, union(bynames, allbyvars)) # TO DO: allbyvars here for vars used by 'by'. Document.
# just using .SD in j triggers all non-by columns in the subset even if some of
# those columns are not used. It would be tricky to detect whether the j expression
# really does use all of the .SD columns or not, hence .SDcols for grouping
# over a subset of columns