thanks a million for solving this problem for me! I really appreciate it.

best,
Christina K.
ck4545@gmail.com
P Please consider the environment - Do you really need to print this email?



On Mar 30, 2010, at 5:44 PM, Gabor Grothendieck wrote:

> The problem is that chron uses 30 as the cutoff year for two digit
> years.  If the year is prior to 30 it adds 2000 to the two digit year
> to get the 4 digit year and if the 2 digit year is 30 or more it adds
> 1900 to the two digit year to get the 4 digit year.  In the line
> marked ######### we convert the two digit years to 4 digit years so
> there is no ambiguity.  (..)$ matches the last two characters and
> "19\\1" means 19 followed by the first back reference where a back
> reference means the part within parentheses in the match to the
> pattern.
> 
>> Lines <- "Date     Time Value
> + 12/31/29 21:00:00   1.4
> + 12/31/29 22:00:00   1.4
> + 12/31/29 23:00:00   1.5
> + 01/01/30 00:00:00   1.6
> + 01/01/30 01:00:00   1.7
> + 01/01/30 02:00:00   1.7
> + 01/01/30 03:00:00   1.8
> + 01/01/30 04:00:00   1.7
> + 01/01/30 05:00:00   1.6
> + 01/01/30 06:00:00   1.5"
>> library(zoo)
>> library(chron)
>> DF <- read.table(textConnection(Lines), header = TRUE, as.is = TRUE)
>> DF$Date <- sub("(..)$", "19\\1", DF$Date)  ##########
>> z <- zoo(DF$Value, chron(DF$Date, DF$Time))
>> z
> (12/31/29 21:00:00) (12/31/29 22:00:00) (12/31/29 23:00:00) (01/01/30 00:00:00)
>                1.4                 1.4                 1.5                 1.6
> (01/01/30 01:00:00) (01/01/30 02:00:00) (01/01/30 03:00:00) (01/01/30 04:00:00)
>                1.7                 1.7                 1.8                 1.7
> (01/01/30 05:00:00) (01/01/30 06:00:00)
>                1.6                 1.5
> 
> 
> On Tue, Mar 30, 2010 at 5:21 PM, Christina Karamperidou
> <ck4545@gmail.com> wrote:
>> true, sorry, I posted a few minutes ago the code for going from 1929 to
>> 1930, and it is not working on my computer. so, when I use the full record,
>> z goes from 1930 to 2005, and then jumps to what it perceives to be 2013 and
>> takes it all the way to 2029 (when in reality it is 1913 to 1929)
>> Lines <- "Date     Time Value
>> 12/31/29 21:00:00   1.4
>> 12/31/29 22:00:00   1.4
>> 12/31/29 23:00:00   1.5
>> 01/01/30 00:00:00   1.6
>> 01/01/30 01:00:00   1.7
>> 01/01/30 02:00:00   1.7
>> 01/01/30 03:00:00   1.8
>> 01/01/30 04:00:00   1.7
>> 01/01/30 05:00:00   1.6
>> 01/01/30 06:00:00   1.5"
>> DF <- read.table(textConnection(Lines), header = TRUE, as.is = TRUE)
>> library(zoo)
>> library(chron)
>> z <- zoo(DF$Value, chron(DF$Date, DF$Time))
>> z
>> (01/01/30 00:00:00) (01/01/30 01:00:00) (01/01/30 02:00:00) (01/01/30
>> 03:00:00) (01/01/30 04:00:00)
>>                 1.6                 1.7                 1.7
>> 1.8                 1.7
>> (01/01/30 05:00:00) (01/01/30 06:00:00) (12/31/29 21:00:00) (12/31/29
>> 22:00:00) (12/31/29 23:00:00)
>>                 1.6                 1.5                 1.4
>> 1.4                 1.5
>> 
>> Christina K.
>> ck4545@gmail.com
>> P Please consider the environment - Do you really need to print this email?
>> 
>> 
>> On Mar 30, 2010, at 5:13 PM, Gabor Grothendieck wrote:
>> 
>> What is the problem?  The code in your post seems to work fine:
>> 
>> Lines <- "Date     Time Value
>> 
>> + 12/31/99 22:00:00   1.8
>> + 12/31/99 23:00:00   1.9
>> + 01/01/00 00:00:00   1.8
>> + 01/01/00 01:00:00   1.7
>> + 01/01/00 02:00:00   1.6
>> + 01/01/00 03:00:00   1.5
>> + 01/01/00 04:00:00   1.4
>> + 01/01/00 05:00:00   1.4"
>> 
>> DF <- read.table(textConnection(Lines), header = TRUE, as.is = TRUE)
>> 
>> library(zoo)
>> 
>> library(chron)
>> 
>> z <- zoo(DF$Value, chron(DF$Date, DF$Time))
>> 
>> z
>> 
>> (12/31/99 22:00:00) (12/31/99 23:00:00) (01/01/00 00:00:00) (01/01/00
>> 01:00:00)
>>                1.8                 1.9                 1.8
>>                 1.7
>> (01/01/00 02:00:00) (01/01/00 03:00:00) (01/01/00 04:00:00) (01/01/00
>> 05:00:00)
>>                1.6                 1.5                 1.4
>>                 1.4
>> 
>> On Tue, Mar 30, 2010 at 4:33 PM, Christina Karamperidou
>> <ck4545@gmail.com> wrote:
>> 
>> Truly sorry about before.
>> 
>> So, it works perfectly fine when I do it at the turn of the century, but
>> 
>> still when I try it on my full record, I get the same problem. Maybe it is
>> 
>> reading in the table in a wrong way. I just read it in as
>> 
>> DF <- read.table("myfile.dat", header = TRUE, as.is = TRUE)
>> 
>> maybe I should just cut and paste parts of z and get it to start in 1913...
>> 
>> I really appreciate your time. thx
>> 
>> Lines <- "Date     Time Value
>> 
>> 12/31/99 22:00:00   1.8
>> 
>> 12/31/99 23:00:00   1.9
>> 
>> 01/01/00 00:00:00   1.8
>> 
>> 01/01/00 01:00:00   1.7
>> 
>> 01/01/00 02:00:00   1.6
>> 
>> 01/01/00 03:00:00   1.5
>> 
>> 01/01/00 04:00:00   1.4
>> 
>> 01/01/00 05:00:00   1.4"
>> 
>> DF <- read.table(textConnection(Lines), header = TRUE, as.is = TRUE)
>> 
>> library(zoo)
>> 
>> library(chron)
>> 
>> z <- zoo(DF$Value, chron(DF$Date, DF$Time))
>> 
>> z
>> 
>> Christina K.
>> 
>> ck4545@gmail.com
>> 
>> P Please consider the environment - Do you really need to print this email?
>> 
>> 
>> On Mar 30, 2010, at 3:48 PM, Gabor Grothendieck wrote:
>> 
>> Not for me.
>> 
>> Please provide your data and code in reproducible form as per last
>> 
>> line of every r-help message and the posting guide.
>> 
>> Lines <- "Date     Time Value
>> 
>> + 01/01/13 00:00:00   1.6
>> 
>> + 01/01/13 01:00:00   1.6
>> 
>> + 01/01/13 02:00:00   1.6
>> 
>> + 01/01/13 03:00:00   1.6
>> 
>> + 01/01/13 04:00:00   1.6
>> 
>> + 01/01/13 05:00:00   1.6
>> 
>> + 01/01/13 06:00:00   1.6
>> 
>> + 01/01/13 07:00:00   1.6
>> 
>> + 01/01/13 08:00:00   1.6
>> 
>> + 01/01/13 09:00:00   1.6"
>> 
>> DF <- read.table(textConnection(Lines), header = TRUE, as.is = TRUE)
>> 
>> library(zoo)
>> 
>> Warning message:
>> 
>> closing unused connection 3 (Lines)
>> 
>> library(chron)
>> 
>> z <- zoo(DF$Value, chron(DF$Date, DF$Time))
>> 
>> z
>> 
>> (01/01/13 00:00:00) (01/01/13 01:00:00) (01/01/13 02:00:00) (01/01/13
>> 
>> 03:00:00)
>> 
>>                1.6                 1.6                 1.6
>> 
>>                 1.6
>> 
>> (01/01/13 04:00:00) (01/01/13 05:00:00) (01/01/13 06:00:00) (01/01/13
>> 
>> 07:00:00)
>> 
>>                1.6                 1.6                 1.6
>> 
>>                 1.6
>> 
>> (01/01/13 08:00:00) (01/01/13 09:00:00)
>> 
>>                1.6                 1.6
>> 
>> 
>> On Tue, Mar 30, 2010 at 3:32 PM, Christina Karamperidou
>> 
>> <ck4545@gmail.com> wrote:
>> 
>> Dear all,
>> 
>> I have a time series of daily measurements that starts like this:
>> 
>> KWhourly[1:10,]
>> 
>>       Date     Time Value
>> 
>> 01/01/13 00:00:00   1.6
>> 
>> 01/01/13 01:00:00   1.6
>> 
>> 01/01/13 02:00:00   1.6
>> 
>> 01/01/13 03:00:00   1.6
>> 
>> 01/01/13 04:00:00   1.6
>> 
>> 01/01/13 05:00:00   1.6
>> 
>> 01/01/13 06:00:00   1.6
>> 
>> 01/01/13 07:00:00   1.6
>> 
>> 01/01/13 08:00:00   1.6
>> 
>> 01/01/13 09:00:00   1.6
>> 
>> I am trying to get average daily, monthly, yearly values using the zoo
>> 
>> package.
>> 
>> My series starts at 01/01/13 00:00:00   and ends at   12/31/05 23:00:00
>> 
>> I create the zoo object:
>> 
>> #z <- zoo(KWhourly$Value,chron(KWhourly$Date, KWhourly$Time))
>> 
>> but then z starts at:
>> 
>> start(z)
>> 
>> [1] (01/01/30 00:00:00)
>> 
>> and ends at:
>> 
>> end(z)
>> 
>> [1] (12/31/29 23:00:00)
>> 
>> instead of going from 01/01/13 to 12/31/05
>> 
>> any ideas why this is happening and how to fix it?
>> 
>> I really appreciate your help
>> 
>> 
>> Christina K.
>> 
>> Columbia University
>> 
>> ck4545@gmail.com
>> 
>> P Please consider the environment - Do you really need to print this email?
>> 
>> 
>> 
>> 
>>        [[alternative HTML version deleted]]
>> 
>> ______________________________________________
>> 
>> R-help@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.
>> 
>> 
>> 
>> 
>> 


	[[alternative HTML version deleted]]

