I'm installing R on an Irix 6.5 machine and R fails to understand dates
prior to 1 Jan 1970. This first cropped up early in the test scripts
(Examples/base-Ex.R):
> > seq(as.Date("1910/1/1"), as.Date("1999/1/1"),
"years")
> Error in fromchar(x) : character string is not in a standard unambiguous
format
The root there is the as.Date("1910/1/1"), which returns that same
error
when entered alone. Any date on or after 1 Jan 1970 works fine; any
before fails with the same error. Obviously, I've not tried every date,
but that seems to be the case.
I got by that test by changing "1910" to "1970", but it
crops up later,
too (reg-tests-1.R):
> > ## Date objects with NA's
> > (t1 <- strptime(c("6. Aug. 1930", "3. Nov.
1925", "28. Mar. 1959",
> + NA, paste(1:29," Feb. 1960",
sep=".")),
> + format = "%d. %b. %Y"))
> [1] "1930-08-06" "1925-11-03" "1959-03-28"
NA "1960-02-01"
> [6] "1960-02-02" "1960-02-03" "1960-02-04"
"1960-02-05" "1960-02-06"
> [11] "1960-02-07" "1960-02-08" "1960-02-09"
"1960-02-10" "1960-02-11"
> [16] "1960-02-12" "1960-02-13" "1960-02-14"
"1960-02-15" "1960-02-16"
> [21] "1960-02-17" "1960-02-18" "1960-02-19"
"1960-02-20" "1960-02-21"
> [26] "1960-02-22" "1960-02-23" "1960-02-24"
"1960-02-25" "1960-02-26"
> [31] "1960-02-27" "1960-02-28" "1960-02-29"
> > stopifnot(6 == length(print(s1 <- summary(t1))),
> + s1== summary(as.POSIXct(t1)),
> + 6 == length(print(format(as.Date(s1)))) )
> Min. 1st Qu. Median Mean 3rd Qu. Max.
> NA NA NA NA NA NA
> Min. 1st Qu. Median Mean 3rd Qu. Max.
> NA NA NA NA NA NA
> Error in if (!(is.logical(r <- eval(ll[[i]])) && all(r)))
stop(paste(deparse(mc[
> [i + :
> missing value where TRUE/FALSE needed
> Execution halted
Interestingly, strptime() seems to return the correct results, as can be
seen in the output above, but the problem occurs in summary() and in
as.POSIXct():
> > summary(t1)
> Min. 1st Qu. Median Mean 3rd Qu. Max.
> NA NA NA NA NA NA
> > as.POSIXct(t1)
> [1] NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA
NA NA
> [26] NA NA NA NA NA NA NA NA
This check, too, can be avoided if I change the dates created:
> > (t1 <- strptime(c("6. Aug. 1970", "3. Nov.
19725", "28. Mar. 1979",
> + NA, paste(1:29," Feb. 1980", sep=".")),
> + format = "%d. %b. %Y"))
> [1] "1970-08-06" "1972-11-03" "1979-03-28"
NA "1980-02-01"
> [6] "1980-02-02" "1980-02-03" "1980-02-04"
"1980-02-05" "1980-02-06"
> [11] "1980-02-07" "1980-02-08" "1980-02-09"
"1980-02-10" "1980-02-11"
> [16] "1980-02-12" "1980-02-13" "1980-02-14"
"1980-02-15" "1980-02-16"
> [21] "1980-02-17" "1980-02-18" "1980-02-19"
"1980-02-20" "1980-02-21"
> [26] "1980-02-22" "1980-02-23" "1980-02-24"
"1980-02-25" "1980-02-26"
> [31] "1980-02-27" "1980-02-28" "1980-02-29"
> > summary(t1)
> Min. 1st Qu.
Median
> "1970-08-06 00:00:00 EDT" "1980-02-05 18:00:00 EST"
"1980-02-13 12:00:00 EST"
> Mean 3rd Qu.
Max.
> "1979-07-28 00:58:07 EDT" "1980-02-21 06:00:00 EST"
"1980-02-29 00:00:00 EST"
> > as.POSIXct(t1)
> [1] "1970-08-06 EDT" "1972-11-03 EST" "1979-03-28
EST" NA
> [5] "1980-02-01 EST" "1980-02-02 EST" "1980-02-03
EST" "1980-02-04 EST"
> [9] "1980-02-05 EST" "1980-02-06 EST" "1980-02-07
EST" "1980-02-08 EST"
> [13] "1980-02-09 EST" "1980-02-10 EST" "1980-02-11
EST" "1980-02-12 EST"
> [17] "1980-02-13 EST" "1980-02-14 EST" "1980-02-15
EST" "1980-02-16 EST"
> [21] "1980-02-17 EST" "1980-02-18 EST" "1980-02-19
EST" "1980-02-20 EST"
> [25] "1980-02-21 EST" "1980-02-22 EST" "1980-02-23
EST" "1980-02-24 EST"
> [29] "1980-02-25 EST" "1980-02-26 EST" "1980-02-27
EST" "1980-02-28 EST"
> [33] "1980-02-29 EST"
Anyone have any ideas?
-Bitt
