I'm using the latest R on Windows XP:
> R.version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major 2
minor 5.0
year 2007
month 04
day 23
svn rev 41293
language R
version.string R version 2.5.0 (2007-04-23)
I understand this:
> .Machine$integer.max
[1] 2147483647
> .Machine$sizeof.longlong
[1] 8
So how can I get a "longlong" (i.e., 64-bit = 8-byte integers) in my
environment? Where is there no storage.mode of "longlong" or
"int64"?
I'm reading electrophysiology data with a time stamp that's in a 64-bit
integer (it's a microsecond clock count) but I'm getting negative values
returned in R:
# Why no warning if this call doesn't return an 8-byte integer?
TimeStamp <- readBin(connection, integer(), size=8, 1)
[1] -311761023
[1] -311756172
I can get the hex values of these numbers like this:
TimeStamp <- readBin(connection, raw(), 8)
[1] 81 e7 6a ed 01 00 00 00
[1] 74 fa 6a ed 01 00 00 00
I can see what these number should be by converting to decimal in Excel:
=HEX2DEC("01ed6ae781")
8278173569
=HEX2DEC("01ed6afa74")
8278178420
How can I get these 8-byte integers in R so I don't have to use this ugly
kludge?
# KLUDGE
TimeStamp <- readBin(connection, integer(), size=4, 2)
> TimeStamp
[1] -311761023 1
# Convert integers to doubles since a double has larger range for integers
than 32-bit integers:>storage.mode(TimeStamp) <- "double"
# This seems to work, but is too ugly:> TimeStamp[2]*2^32 + (2^32 + TimeStamp[1])
[1] 8278173569
Can anyone suggest a better way?
Thanks for any suggestions.
efg
Earl F. Glynn
Stowers Institute for Medical Research
