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

[Cat Cowie]

Hi Gerrit,

Thanks for your quick reply - this, in combination with reversing the
date as it is shown in my data, worked perfectly.

startt<- strptime((paste(data2$V4, data2$V5)), "%Y-%m-%d %H:%M:%S")

Apologies for the silly question it seems, but you've saved me a lot
of time. Always learning....
Thanks, Cat



On 12 April 2013 15:00, Gerrit Eichner
<Gerrit.Eichner at math.uni-giessen.de> wrote:
> 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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