Functions to operate on nanosecond time resolution using integer64 bit representation. Conversion functions for several standard R types are provided, and more will be added as needed.
as.integer64 conversion helper returning the underlying
integer64 representation
nanotime(x, ...)# S4 method for character
nanotime(x, format = "", tz = "")
nanotime.matrix(x)
# S4 method for POSIXct
nanotime(x)
# S4 method for POSIXlt
nanotime(x)
# S4 method for Date
nanotime(x)
# S4 method for nanotime
print(x, format = "", tz = "", ...)
# S4 method for nanotime
show(object)
# S3 method for nanotime
format(x, format = "", tz = "", ...)
# S3 method for nanotime
index2char(x, ...)
# S3 method for nanotime
as.POSIXct(x, tz = "", ...)
# S3 method for nanotime
as.POSIXlt(x, tz = "", ...)
# S3 method for nanotime
as.Date(x, ...)
# S3 method for nanotime
as.data.frame(x, ...)
# S3 method for nanotime
as.integer64(x, ...)
as.integer64(x, ...)
# S4 method for nanotime,character
-(e1, e2)
# S4 method for nanotime,nanotime
-(e1, e2)
# S4 method for nanotime,integer64
-(e1, e2)
# S4 method for nanotime,numeric
-(e1, e2)
# S4 method for ANY,nanotime
-(e1, e2)
# S4 method for nanotime,ANY
-(e1, e2)
# S4 method for nanotime,ANY
+(e1, e2)
# S4 method for nanotime,integer64
+(e1, e2)
# S4 method for nanotime,numeric
+(e1, e2)
# S4 method for ANY,nanotime
+(e1, e2)
# S4 method for integer64,nanotime
+(e1, e2)
# S4 method for numeric,nanotime
+(e1, e2)
# S4 method for nanotime,nanotime
+(e1, e2)
# S4 method for nanotime,ANY
Arith(e1, e2)
# S4 method for ANY,nanotime
Arith(e1, e2)
# S4 method for nanotime,ANY
Compare(e1, e2)
# S4 method for nanotime,ANY
Logic(e1, e2)
# S4 method for ANY,nanotime
Logic(e1, e2)
# S4 method for nanotime
Math(x)
# S4 method for nanotime
Math2(x, digits)
# S4 method for nanotime
Summary(x, ..., na.rm = FALSE)
# S4 method for nanotime
min(x, ..., na.rm = FALSE)
# S4 method for nanotime
max(x, ..., na.rm = FALSE)
# S4 method for nanotime
range(x, ..., na.rm = FALSE)
# S4 method for nanotime
Complex(z)
# S4 method for nanotime
[(x, i, j, ..., drop = FALSE)
# S4 method for nanotime
[(x, i, j, ...) <- value
# S3 method for nanotime
c(...)
# S4 method for nanotime
names(x) <- value
# S4 method for nanotime
is.na(x)
The object which want to convert to class nanotime
further arguments passed to or from methods.
A character string. Can also be set via options("nanotimeFormat")
and uses ‘%Y-%m-%dT%H:%M:%E9S%Ez’ as a default and fallback
Required for as.POSIXct and as.POSIXlt,
can be set via options("nanotimeTz") and uses ‘UTC’ as
a default and fallback
argument for method show
Operand of class nanotime
Operand of class nanotime
Required for Math2 signature but ignored here
a logical indicating whether missing values should be removed.
Required for Complex signature but ignored here
index specifying elements to extract or replace.
Required for [ signature but ignored here
Required for [ signature but ignored here
argument for nanotime-class
A nanotime object
Working with dates and times is difficult. One
needs a representation of both time points and
time duration. In R, think of Date or
POSIXct objects for the former, and difftime
for the later. Here we (currently) only have time points,
but they are effectively also durations relative to the
epoch of January 1, 1970.
There are two external libraries doing two key components.
We rely on the bit64 package for integer64
types to represent nanoseconds relative to the epoch. This is
similar to POSIXct which uses fractional seconds since the
epoch---so here we are essentially having the same values, but
multiplied by 10 to the power 9 and stored as integers. We need
to rely on the external package as we require 64-bit integers
whereas R itself only has 32-bit integers. The
bit64 package is clever about how it manages to
provide such an integer using only the 64-bit double type and very
clever (and efficient) transformations.
The other is the CCTZ library in C++, which we access via the
RcppCCTZ package. CCTZ extends the C++11 standard
library type chrono type in very useful ways for time zones and
localtime. We use its formating and parsing features.
Formatting and character conversion for nanotime objects is
done by functions from the RcppCCTZ package relying
on code from its embedded CCTZ library. The default format
is ISO3339 compliant: %Y-%m-%dT%H:%M:%E9S%Ez. It
specifies a standard ISO 8601 part for date and time --- as well
as nine digits of precision for fractional seconds (down to
nanoseconds) and on offset (typically zero as we default to UTC).
It can be overriden by using options() with the key of
nanotimeFormat and a suitable value. Similarly,
nanotimeTz can be used to select a different timezone.
Notice that the conversion from POSIXct explicitly sets the last three digits to zero. Nanosecond time stored in a 64-bit integer has nineteen digits precision where doubles (which are used internally for POSIXct as well) only have sixteen digits. So rather than showing three more (essentially random) digits it is constructed such that these three additional digits are zeros.
# NOT RUN {
x <- nanotime("1970-01-01T00:00:00.000000001+00:00")
print(x)
x <- x + 1
print(x)
format(x)
x <- x + 10
print(x)
format(x)
format(nanotime(Sys.time()) + 1:3) # three elements each 1 ns apart
# }
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