bReeze (version 0.4-1)

timestamp: Format time stamps

Description

Converts time stamps from string to POSIXlt. The conversion specification (pattern) is looked up if not given as argument.

Usage

timestamp(timestamp, pattern, tz)
ts(timestamp, pattern, tz)

Arguments

timestamp

Time stamp as string vector.

pattern

Conversion specification of time stamp as string (optional). See Details for usage.

tz

Optional character string specifying the time zone to be used for the conversion. System-specific (see as.POSIXlt), but "" is the current time zone (used as default). Use "?" to check timestamp for time zone abbreviation.

Value

Returns a POSIXlt vector.

Details

If the time stamp is already formatted as POSIXlt, the usage of timestamp is not necessary. strptime can also be used to create an applicable time stamp. Usage of timestamp is recommeded, since it checks the created time stamp, thus faulty time stamps are avoided.

Pattern

A conversion specification is introduced by "%", usually followed by a single letter. Any character in the format string not part of a conversion specification is interpreted literally. Widely implemented conversion specifications include:

• %d: day of the month as decimal number (01--31)

• %m: month as decimal number (01--12)

• %y: year without century (00--99), where values 00--68 are prefixed by 20 and 69--99 by 19

• %Y: year with century

• %H: hour as decimal number (00--23)

• %M: minute as decimal number (00--59)

• %S: second as decimal number (00--61)

For details see strptime.

See Also

POSIXlt, strptime, mast

Examples

# NOT RUN {
# load and prepare data
data(winddata)

# format time stamp
timestamp <- timestamp(timestamp=winddata[,1])

# format time stamp with given pattern
timestamp.2 <- timestamp(timestamp=winddata[,1], "%d.%m.%Y %H:%M")

# wrong pattern (<!-- %y) -->
timestamp.2 <- timestamp(timestamp=winddata[,1], "%d.%m.%y %H:%M")

# strange time stamp pattern
ts <- c("TS 08/2012-10 8h10m30s", "TS 08/2012-10 8h20m30s", 
  "TS 08/2012-10 8h30m30s")
timestamp.3 <- timestamp(timestamp=ts)	# pattern not found
timestamp.3 <- timestamp(timestamp=ts, "TS %m/%Y-%d %Hh%Mm%Ss")

# time zones
# manually define time zone
timestamp.4 <- timestamp(timestamp=winddata[,1], tz="CET")

# get time zone from timestamp
timestamp.5 <- timestamp(timestamp="2012-08-08 22:55 GMT", tz="?")
# }