seq.Date(*, by = <abbreviated>); docu+checks also for seq.POSIX

git-svn-id: https://svn.r-project.org/R/trunk@87537 00db46b3-68df-0310-9c12-caf00c1e9a41

doc/NEWS.Rd

@@ -156,6 +156,9 @@
       The \code{Date} method also works for \code{seq(from, to)}, when
       \code{by} is missing and now defaults to \code{"1 days"}.
 
+      It is now documented (and tested) that the \code{by} string may be
+      \emph{abbreviated} in both \code{seq} methods.
+
       Both methods return or keep internal type \code{"integer"} more
       consistently now.  Also, \code{as.POSIXct({})} is internally integer.
     }

src/library/base/R/dates.R

@@ -270,13 +270,15 @@ seq.Date <- function(from, to, by, length.out = NULL, along.with = NULL, ...)
         units(by) <- "days"
         by <- as.vector(by)
     } else if(is.character(by)) {
-        by2 <- strsplit(by, " ", fixed = TRUE)[[1L]]
-        if(length(by2) > 2L || length(by2) < 1L)
+        nby2 <- length(by2 <- strsplit(by, " ", fixed = TRUE)[[1L]])
+        if(nby2 > 2L || nby2 < 1L)
             stop("invalid 'by' string")
-        valid <- pmatch(by2[length(by2)],
-                        c("days", "weeks", "months", "quarters", "years"))
+        bys <- c("days", "weeks", "months", "quarters", "years")
+        valid <- pmatch(by2[nby2], bys) 
         if(is.na(valid)) stop("invalid string for 'by'")
+        by <- bys[valid] # had *partial* match
         if(valid > 2L) { # seq.POSIXt handles the logic for non-arithmetic cases
+            if (nby2 == 2L) by <- paste(by2[1L], by)
             res <- switch(missing_arg,
               from       = seq(to   = as.POSIXlt(to),   by = by,             length.out = length.out),
               to         = seq(from = as.POSIXlt(from), by = by,             length.out = length.out),
@@ -285,7 +287,7 @@ seq.Date <- function(from, to, by, length.out = NULL, along.with = NULL, ...)
             return(as.Date(res))
         }
         by <- c(1L, 7L)[valid]
-        if (length(by2) == 2L) by <- by * as.integer(by2[1L])
+        if (nby2 == 2L) by <- by * as.integer(by2[1L])
     }
     else if(!is.numeric(by)) stop("invalid mode for 'by'")
     if(is.na(by)) stop("'by' is NA")

src/library/base/R/datetime.R

@@ -1004,6 +1004,7 @@ function(from, to, by, length.out = NULL, along.with = NULL, ...)
        )
        return(.POSIXct(res, tz))
     }
+    ## months or longer -->  via  POSIXlt
     lres <- as.POSIXlt(if (missing_arg != "from") from else to)
     if (missing_arg == "length.out") lto <- as.POSIXlt(to)
     if(valid == 7L) { # years

src/library/base/man/seq.Date.Rd

@@ -27,7 +27,8 @@
     \item A number, taken to be in days.
     \item A object of class \code{\link{difftime}}
     \item A character string, containing one of \code{"day"},
-    \code{"week"}, \code{"month"}, \code{"quarter"} or \code{"year"}.
+    \code{"week"}, \code{"month"}, \code{"quarter"} or \code{"year"}, or a
+    \code{\link{pmatch}()}able abbreviaton of these.
     This can optionally be preceded by a (positive or negative) integer
     and a space, or followed by \code{"s"}.
 
@@ -55,11 +56,15 @@ seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by = "quarter")
 ## 3-week period ending on a fixed date
 seq(to = as.Date("2024-06-18"), by = "day", length.out = 21)
 
-## find all 7th of the month between two dates, the last being a 7th.
+## find all 7th of the month _strictly_ inside two dates, the last being a 7th.
 st <- as.Date("1998-12-17")
 en <- as.Date("2000-1-7")
 ll <- seq(en, st, by = "-1 month")
-rev(ll[ll > st & ll < en])
+rev(ll[st < ll & ll < en])
+
+## can abbreviate 'month' to 'm':
+identical(seq(st, en, by = "m"),
+          seq(st, en, by = "1 month"))
 }
 \keyword{manip}
 \keyword{chron}

src/library/base/man/seq.POSIXt.Rd

@@ -27,7 +27,8 @@
     \item An object of class \code{\link{difftime}}
     \item A character string, containing one of \code{"sec"},
     \code{"min"}, \code{"hour"}, \code{"day"}, \code{"DSTday"},
-    \code{"week"}, \code{"month"}, \code{"quarter"} or \code{"year"}.
+    \code{"week"}, \code{"month"}, \code{"quarter"} or \code{"year"}, or a
+    \code{\link{pmatch}()}able abbreviaton of these.
     This can optionally be preceded by a (positive or negative) integer
     and a space, or followed by \code{"s"}.
   }

tests/datetime3.R

@@ -683,6 +683,8 @@ All.eq0 <- function(x,y, ...) all.equal(x, y, tolerance = 0, ...)
 stopifnot(exprs = {
   ## NB: use 'from' on LHS of reference to ensure the time zone of 'from' is used in the result
   identical(seq(from, to, by=by), from + wks2sec*(0:4))
+  identical(seq(from, to, by=by),
+            seq(from, to, by="2 w")) # may abbreviate
   identical(seq(from, to, length.out=length.out),
             from + seq(0, difftime(to, from, units="secs"), length.out=length.out))
   ##
@@ -732,11 +734,16 @@ stopifnot(exprs = {
   ## variations on 'by'
   identical(seq(from, to, by='2 months'), from + c(0, c(31+29)))
   identical(seq(to, from, by='-2 months'), to - c(0, c(31+29)))
+  identical(seq(to, from, by='-2 m'     ), to - c(0, c(31+29)))
   identical(seq(from, to, by=as.difftime(30, units='days')), from + 30*(0:2))
   identical(seq(from, to, by=30), from + 30*(0:2))
+  all.equal(seq(from, to, by = "1 week"), seq(from, by = "w", length.out = 9)) # TODO ident. ?
+  identical(seq(frI, toI, by = "1 week"), seq(from, by = "w", length.out = 9))
   ##
   ## missing from=
-  All.eq0 ( seq(to=to, by='day',     length.out=6), to - (5:0))
+  identical(seq(to=to, by='day',     length.out=6),
+            seq(to=to,               length.out=6))
+  All.eq0 ( seq(to=to,               length.out=6), to - (5:0))
   All.eq0 ( seq(to=to, by='-3 days', length.out=6), to + 3*(5:0))
   identical(seq(to=to, by='2 months',length.out=3), to - c(31+29+31+30, 31+29, 0))
   identical(seq(to=to, by='quarter', length.out=3), to - c(31+29+31+30+31+30, 31+29+31, 0))