[R] converting character matrix to POSIXct matrix

Rui Barradas ruipbarradas at sapo.pt
Fri Apr 26 23:24:54 CEST 2013


Hello,

You should keep this on the list, the odds of getting more and better 
answers are greater.
I don't know if the following is what you want.

apply(time.m, 2,  function(tt) as.POSIXct(tt, format = "%H:%M:%OS"))


Hope this helps,

Rui Barradas

Em 26-04-2013 21:49, hh wt escreveu:
> sapply doesn't do it.  It just spits out the guts,
>
> $`08:00:20.799.sec`
> [1] 20.799
>
> $`08:00:20.799.min`
> [1] 0
>
> $`08:00:20.799.hour`
> [1] 8
>
> $`08:00:20.799.mday`
> [1] 26
>
> $`08:00:20.799.mon`
> [1] 3
>
> $`08:00:20.799.year`
> [1] 113
>
>
> On Fri, Apr 26, 2013 at 11:25 AM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
>
>> Hello,
>>
>> Use sapply instead.
>>
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>> Em 26-04-2013 18:51, hh wt escreveu:
>>
>>> I thought this is a common question but rseek/google searches don't yield
>>> any relevant hit.
>>>
>>> I have a matrix of character strings, which are time stamps,
>>>
>>>   time.m[1:5,1:5]
>>>>
>>>        [,1]           [,2]           [,3]           [,4]           [,5]
>>>
>>> [1,] "08:00:20.799" "08:00:20.799" "08:00:20.799" "08:00:20.799"
>>> "08:00:20.799"
>>> [2,] "08:00:21.996" "08:00:22.071" "08:00:23.821" "08:00:24.370"
>>> "08:00:25.573"
>>> [3,] "08:00:29.200" "08:00:29.200" "08:00:29.591" "08:00:30.368"
>>> "08:00:30.536"
>>> [4,] "08:00:31.073" "08:00:31.372" "08:00:31.384" "08:00:31.403"
>>> "08:00:31.867"
>>> [5,] "08:00:31.867" "08:00:31.867" "08:00:31.971" "08:00:34.571"
>>> "08:00:34.571"
>>>
>>> And i would like to convert it to a POSIXct matrix. I tried this,
>>>
>>> time1 = lapply(time.m, function(tt)strptime(tt, "%H:%M:%OS"))
>>>
>>> but it yields a list.
>>>
>>> Any tip is appreciated.
>>>
>>>
>>> Horace
>>>
>>>          [[alternative HTML version deleted]]
>>>
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