[R] Creating "%d/%m/%Y %H:%M:%S" format from separate date andtimecolumns

[Gerrit Eichner]

Hello, Cat,

see inline below.

  Hth  --  Gerrit

On Fri, 12 Apr 2013, Cat Cowie wrote:

> Hi R forum,
>
> Each row of my data (below) show a new contact event between animals.
> In order to ultimately look at the patterns of intervals between
> contacts, I need to calculate a contact end time. The contact starts
> at the date and time shown in V4 and V5, and lasts for the duration
> shown IN SECONDS in V6:
>
>
>> data2<- read.csv(file=file.choose(), header=F, sep=" ")
>> head(data2)
>  V1  V2  V3         V4       V5 V6
> 1  3 PO4 CO1 2011-04-29 07:27:21 28
> 2  3 PO4 CO1 2011-04-24 05:57:39 20
> 3  3 PO4 CO1 2011-04-14 10:29:49  4
> 4  3 PO4 CO1 2011-04-16 07:27:31 63
> 5  3 PO4 CO1 2011-04-18 15:46:20  1
> 6  3 PO4 CO1 2011-04-18 15:45:57  1
>
> To start with I have tried to make the start data and time into one new column:
>
> startt<- strptime((paste(data2$V4, data2$V5)), "%d/%m/%Y %H:%M:%S")

Shouldn't you use "-" instead of "/" as it is used in data$V4?



> This executes without any warnings, but returns a full column of NA
> values. It would be great to fix this, and then to know how to
> correctly add column V6 as seconds to the resulting column.
>
>
> The problem is further exacerbated by an error with dput() with this
> data. It's a large dataset of over 9000 rows, and when I call:
>
> dput(head(data2,50))
>
> It returns dput(), but for all the data (i.e. not the first 50 rows).
> This of course does not fit on the workstation screen and therefore I
> cannot find out what class it has assigned to any of the data. The
> times appear sorted, suggesting they are being classed as a factor?
> Sorry I can't provide dput() data!
>
> Thanks, Cat
>
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