R help - Mar 2012 - read.zoo - combining two columns with date and time respectively into one index column?

I have three columns in my raw data: date, time, and dry bulb temperature:

http://r.789695.n4.nabble.com/file/n4495326/weathDataSDCoron.txt
weathDataSDCoron.txt 

The date format is %Y%m%d and the time format is %H:%M. Any ideas on how to
read it in such that it looks at the first two columns and then merges it
into one column combining both the date and time? 

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I actually just found an alternative solution which involves setting Excel's
or Libre Office Calc's fixed width option then saving it again as a .txt or
.csv. If there's a cleaner way of doing this within the R shell, I'm
open to
ideas.

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On Thu, Mar 22, 2012 at 8:24 AM, knavero <knavero at gmail.com>
wrote:
> I have three columns in my raw data: date, time, and dry bulb temperature:
>
> http://r.789695.n4.nabble.com/file/n4495326/weathDataSDCoron.txt
> weathDataSDCoron.txt
>
> The date format is %Y%m%d and the time format is %H:%M. Any ideas on how to
> read it in such that it looks at the first two columns and then merges it
> into one column combining both the date and time?
index= in read.zoo can be a vector.

library(zoo)
library(chron)

URL <-
"http://r.789695.n4.nabble.com/file/n4495326/weathDataSDCoron.txt"

toChron <- function(d, t) as.chron(paste(d, t), format = "%Y%m%d
%H:%M")
tail1 <- function(x) tail(x, 1)  # for duplicate times take last

z <- read.zoo(URL, index = 1:2, FUN = toChron,
	header = TRUE, sep = "\t", aggregate = tail1)

See ?read.zoo and the zoo-read vignette for many examples.


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Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com

On Mar 22, 2012, at 8:24 AM, knavero wrote:
> I have three columns in my raw data: date, time, and dry bulb  
> temperature:
>
> http://r.789695.n4.nabble.com/file/n4495326/weathDataSDCoron.txt
> weathDataSDCoron.txt
>
> The date format is %Y%m%d and the time format is %H:%M. Any ideas on  
> how to
> read it in such that it looks at the first two columns and then  
> merges it
> into one column combining both the date and time?
I'm reasonably optimistic that read.zoo will do that. It's capable of  
two column datetime reads. My memory is that you just give the column  
numbers to the index.column argument. You will also need to give a  
format argument since your formats to not look to be bog standard.
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/read-zoo-combining-two-columns-with-date-and-time-respectively-into-one-index-column-tp4495326p4495326.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT

Ah yes, sorry about that Gabor. Found a pretty good example in ?read.zoo
where it has index = 1:3 and takes in times objects. I must have overlooked
it out of impatience. Thanks for the quick and simple feedback however.

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