[R] How to convert number (matlab) to date

[Gabor Grothendieck]

On Mon, Jul 18, 2011 at 10:08 AM, peter dalgaard <pdalgd at gmail.com> wrote:
>
> On Jul 18, 2011, at 15:48 , Gabor Grothendieck wrote:
>
>> On Mon, Jul 18, 2011 at 8:56 AM, peter dalgaard <pdalgd at gmail.com> wrote:
>>>
>>> On Jul 18, 2011, at 14:08 , Gabor Grothendieck wrote:
>>>
>>>> On Sat, Jul 16, 2011 at 11:50 PM, Eduardo M. A. M. Mendes
>>>> <emammendes at gmail.com> wrote:
>>>>> Hello
>>>>>
>>>>> I am new to R and I need to convert some dates (numeric format by matlab) to actual dates in R.
>>>>>
>>>>> For instance,
>>>>>
>>>>> Matlab -> 730456 -> >> datestr(730456)
>>>>>
>>>>> ans =
>>>>>
>>>>> 02-Dec-1999
>>>>>
>>>>
>>>> Set the origin to Matlab's origin like this.  Be sure you are using
>>>> the indicated version of zoo or later:
>>>>
>>>>> library(zoo)
>>>>> packageVersion("zoo")
>>>> [1] ‘1.7.1’
>>>>> as.Date(730456, origin = "0000-00-00")
>>>> [1] "1999-12-02"
>>>
>>> Doesn't work on a Mac, and in general, I think it depends on a quirk in your OS's date conversion utilities. What does work for me is
>>
>> Did you have zoo 1.7-1 loaded?  What happens when you try it?
>
>
> I did, actually:
>
>> packageVersion("zoo")
> [1] ‘1.7.1’
>> as.Date('00-00-0000')
> Error in charToDate(x) :
>  character string is not in a standard unambiguous format
>> as.Date('0000-00-00')
> Error in charToDate(x) :
>  character string is not in a standard unambiguous format
>> as.Date(1, origin='0000-00-00')
> Error in charToDate(x) :
>  character string is not in a standard unambiguous format
>> as.Date(730456, origin='0000-00-00')
> Error in charToDate(x) :
>  character string is not in a standard unambiguous format
>
> .....
>
> However, this was after reinstalling and reloading zoo. Restarting R and retrying did indeed make things work.
>

Does the fact that it worked if R was restarted, but not without,
imply that there is something in R that needs to be fixed?

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