Extracting Current and Old Date

If I read this correctly:

mydates <- as.Date(c("2007-06-22", "2007-05-21", "2004-04-13",
"2004-03-11","2004-02-13"))
xx  <-  min(mydates)
yy  <-  max(mydates)
yy-xx

John Kane
Kingston ON Canada

-----Original Message-----
From: pmaclean2011 at yahoo.com
Sent: Sun, 28 Jul 2013 12:20:30 -0700 (PDT)
To: r-help at r-project.org
Subject: Re: [R] Extracting Current and Old Date

#This my look trivial but has been killing my time
#I want to extract most current and old date from mydates #variable that
has more than 10,000 observation.
#Get days
# use as.Date( ) to convert strings to dates
mydates <- as.Date(c("2007-06-22", "2007-05-21", "2004-04-13",
"2004-03-11","2004-02-13",))
#Is there a way/fuction to extract mostcurrent date
#from mydates variable
mostcurrent <- as.Date(c("2007-06-22"))

#Is there a way/function to extract olddate
#from mydates variable
olddate    <- as.Date(c("2004-02-13"))

#Days between most current and old dayte
days <- as.numeric(mostcurrent - olddate)


Peter Maclean
Department of Economics
UDSM
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#This my look trivial but has been killing my time
#I want to extract most current and old date from mydates #variable that has more than 10,000 observation. 
#Get days
# use as.Date( ) to convert strings to dates 
mydates <- as.Date(c("2007-06-22", "2007-05-21", "2004-04-13", "2004-03-11","2004-02-13",))
#Is there a way/fuction to extract mostcurrent date
#from mydates variable
mostcurrent <- as.Date(c("2007-06-22"))

#Is there a way/function to extract olddate 
#from mydates variable
olddate    <- as.Date(c("2004-02-13"))

#Days between most current and old dayte
days <- as.numeric(mostcurrent - olddate)  

The usual ways to work with numeric data have been given .Date methods:

mydates <- as.Date(c("2007-06-22", "2007-05-21", "2004-04-13", "2004-03-11","2004-02-13"))
min(mydates)

[1] "2004-02-13"

max(mydates)

[1] "2007-06-22"

range(mydates)

[1] "2004-02-13" "2007-06-22"

diff(range(mydates))

Time difference of 1225 days

David Winsemius
Alameda, CA, USA

Hi,

?max
?min

max(mydates)
#[1] "2007-06-22"
min(mydates)
#[1] "2004-02-13"
?max(mydates)-min(mydates)
Time difference of 1225 days
?max(as.numeric(mydates))-min(as.numeric(mydates))
#[1] 1225
A.K.


----- Original Message -----
From: Peter Maclean <pmaclean2011 at yahoo.com>
To: "r-help at r-project.org" <r-help at r-project.org>
Cc: 
Sent: Sunday, July 28, 2013 3:20 PM
Subject: Re: [R] Extracting Current and Old Date

#This my look trivial but has been killing my time
#I want to extract most current and old date from mydates #variable that has more than 10,000 observation.?
#Get days
# use as.Date( ) to convert strings to dates 
mydates <- as.Date(c("2007-06-22", "2007-05-21", "2004-04-13", "2004-03-11","2004-02-13",))
#Is there a way/fuction to extract mostcurrent date
#from mydates variable
mostcurrent <- as.Date(c("2007-06-22"))

#Is there a way/function to extract olddate 
#from mydates variable
olddate??? <- as.Date(c("2004-02-13"))

#Days between most current and old dayte
days <- as.numeric(mostcurrent - olddate) ?


Peter Maclean
Department of Economics
UDSM
??? [[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.