(I've put the R Mac list in cc because of the crashes I have
experienced trying some of the suggestions below)
Hi Gabor and Prof Ripley,
Le 31 janv. 08 ? 02:11, Prof Brian Ripley a ?crit :
The output from sessionInfo() the posting guide asked for would have
been very helpful here.
You are right, sorry about that:
> library(chron)
> sessionInfo()
R version 2.6.1 (2007-11-26)
i386-apple-darwin8.10.1
locale:
fr_FR.UTF-8/fr_FR.UTF-8/fr_FR.UTF-8/C/fr_FR.UTF-8/fr_FR.UTF-8
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] chron_2.3-16
I think the problem is likely to be that these are not standard French
abbreviations according to my systems.
I was ready to blame Excel for the use of non-standard abbreviations,
but I would have been wrong: it seems that "janv" is a Mac OS X
decision from what I can see in my system settings. I am not sure what
would be a bullet-proof authority on french abbreviations. My
dictionary was of no help, but wikipedia seems to endorse Mac OS X and
Windows use of "janv":
<http://fr.wikipedia.org/wiki/Mois#Abr.C3.A9viations>
On Linux I get
format(Sys.Date(), "%d-%b-%y")
[1] "31-jan-08"
format(Sys.Date()-50, "%d-%b-%y")
[1] "12-d?c-07"
and on Windows
format(Sys.Date(), "%d-%b-%y")
[1] "31-janv.-08"
format(Sys.Date()-50, "%d-%b-%y")
[1] "12-d?c.-07"
I tried this too:
> format(Sys.Date(), "%d-%b-%y")
[1] "31-jan-08"
> format(Sys.Date()-50, "%d-%b-%y")
[1] "12-d?c-07"
I am lost here: since the OS uses "janv", why did the above give
"jan"???
And yes, chron is US-centric and so only allows English names.
Assuming you know exactly what is meant by 'French short format', I
think the simplest thing to do is to set up a table by
tr <- month.abb
names(tr)[1] <- c("janv") # complete it
x <- "9-janv-08"
x2 <- strsplit(x, "-")
x3 <- sapply(x2, function(x) {x[2] <- tr[x[2]]; paste(x,
collapse="-")})
as.Date(x3, format = "%d-%b-%y")
Thank you Prof Ripley, although I'll have to do my homework to fully
understand what is happening with the function you wrote.
But I wonder why I cannot make this a Date object:
> x <- "9-janv-08"
> x2 <- strsplit(x, "-")
> x3 <- sapply(x2, function(x) {x[2] <- tr[x[2]]; paste(x,
collapse="-")})
> as.Date(x3, format = "%d-%b-%y")
[1] "2008-01-09"
> class(x3)
[1] "character"
> x4 <- as.Date(x3, format = "%d-%b-%y")
*** caught bus error ***
address 0x8, cause 'non-existent physical address'
Traceback:
1: strptime(x, format)
2: as.Date.character(x3, format = "%d-%b-%y")
3: as.Date(x3, format = "%d-%b-%y")
Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace
The problem may be my system as I get this error when trying Gabor's
suggestions (below).
Le 31 janv. 08 ? 00:21, Gabor Grothendieck a ?crit :
Suppose we have:
dd <- c("7-d?c-07", "11-d?c-07", "14-d?c-07", "18-d?c-07", "21-
d?c-07",
"24-d?c-07", "26-d?c-07", "28-d?c-07", "31-d?c-07", "2-janv-08",
"4-janv-08", "7-janv-08", "9-janv-08", "11-janv-08", "14-janv-08",
"16-janv-08", "18-janv-08")
Try this (where we are assuming the just released chron 2.3-17):
library(chron)
Sys.setlocale("LC_ALL", "French")
as.chron(as.Date(dd, "%d-%b-%y"))
# or with chron 2.3-16 last line is replaced with:
chron(unclass(as.Date(dd, "%d-%b-%y")))
> library(chron)
> dd <- c("7-d?c-07", "11-d?c-07", "14-d?c-07", "18-d?c-07", "21-
d?c-07",
+ "24-d?c-07", "26-d?c-07", "28-d?c-07", "31-d?c-07", "2-janv-08",
+ "4-janv-08", "7-janv-08", "9-janv-08", "11-janv-08", "14-janv-08",
+ "16-janv-08", "18-janv-08")
> Sys.setlocale("LC_ALL", "French")
[1] ""
Warning message:
In Sys.setlocale("LC_ALL", "French") :
la requ?te OS pour sp?cifier la localisation ? "French" n'a pas pu
?tre honor?e
> chron(unclass(as.Date(dd, "%d-%b-%y")))
*** caught bus error ***
address 0x8, cause 'non-existent physical address'
Traceback:
1: strptime(x, format)
2: as.Date.character(dd, "%d-%b-%y")
3: as.Date(dd, "%d-%b-%y")
4: inherits(dates., "dates")
5: chron(unclass(as.Date(dd, "%d-%b-%y")))
Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace
If those don't work (the above didn't work on my Vista system but this
is system dependent and
might work on yours) then try this alternative
Again, this Sys.setlocale call does not work for me and the use of
as.Date crashes my copy of R:
> library(chron)
> library(gsubfn)
Le chargement a n?cessit? le package : proto
> french.months <- format(seq(as.Date("2000-01-01"), length = 12, by
= "month"), "%b")
*** caught bus error ***
address 0x8, cause 'non-existent physical address'
Traceback:
1: strptime(x, f)
2: fromchar(x)
3: as.Date.character("2000-01-01")
4: as.Date("2000-01-01")
5: seq(as.Date("2000-01-01"), length = 12, by = "month")
6: format(seq(as.Date("2000-01-01"), length = 12, by = "month"),
"%b")
Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace
However, if I replace that call by this, the rest of Gabor's solution
works.
> library(chron)
> library(gsubfn)
Le chargement a n?cessit? le package : proto
> french.months <- c("janv", "f?v", "mars", "avr", "mai", "juin",
"juil", "ao?t", "sept", "oct", "nov", "d?c")
> dd <- c("7-d?c-07", "11-d?c-07", "14-d?c-07", "18-d?c-07", "21-
d?c-07",
+ "24-d?c-07", "26-d?c-07", "28-d?c-07", "31-d?c-07", "2-janv-08",
+ "4-janv-08", "7-janv-08", "9-janv-08", "11-janv-08", "14-janv-08",
+ "16-janv-08", "18-janv-08")
> f <- function (d, m, y) chron(paste(pmatch(m, french.months), d, y,
sep = "/"))
> strapply(dd, "(.*)-(.*)-(.*)", f, backref = -3, simplify = c)
[1] 12/07/07 12/11/07 12/14/07 12/18/07 12/21/07 12/24/07 12/26/07
12/28/07
[9] 12/31/07 01/02/08 01/04/08 01/07/08 01/09/08 01/11/08 01/14/08
01/16/08
[17] 01/18/08
So thanks again. I will try to reinstall R on my computer and see if I
still get these errors.
Denis
On Jan 30, 2008 11:29 PM, Denis Chabot <chabotd at globetrotter.net>
wrote:
Hello R users,
I have to import a file with one column containing dates written in
French short format, such as:
7-d?c-07
11-d?c-07
14-d?c-07
18-d?c-07
21-d?c-07
24-d?c-07
26-d?c-07
28-d?c-07
31-d?c-07
2-janv-08
4-janv-08
7-janv-08
9-janv-08
11-janv-08
14-janv-08
16-janv-08
18-janv-08
There are other columns for other (numeric) variables in the data
file. In my read.csv2 statement, I indicate that the date column must
be imported "as.is" to keep it as character.
I would like to transform this into a date object in R. So far I've
used chron for my dates and times needs, but I am willing to change
if
another object/package will ease the task of importing these dates.
My reading of the chron help led me to believe that the formats it
understands are only month names in English.
Are there other "formats" I can use with chron, or must I somehow
edit
this character variables to replace French month names by English
ones
(or numbers from 1 to 12)?
Thanks in advance,
Denis
p.s. I read this in digest mode, so I'll get your replies faster if
you cc to my email