[R] coordinates from locator function in POSIXct format

cristabel.duran cristabel.duran at waldbau.uni-freiburg.de
Fri Jul 29 18:21:23 CEST 2011

Hi Janis,
thank you for you answer.

Actually already I did exactly what you said. However, when I convert 
the number of "seconds" from the first measurement (some day in July 
2010) then a I get a date in the year 2050 which is impossible. The 
latest date possible is 29March2011.

my value in ?seconds?: 1285038419
z <- 1285038419
as.POSIXct(z, origin="2010-07-15")
"2051-04-04 03:06:59 CEST"

any clue why I get this date?

I thank your help,


On 07/29/2011 04:45 PM, Jannis wrote:
> Well,if you would have had a look at ?POSIXct the documentation would 
> have given
>  you quite a comprehensive explanation of the meaning of the values of 
> your time vector as they are the values these POSIXct values are 
> actually stored in (they are seconds since 1970-01-01). Additionally 
> you would have been redirected to as.POSIXct() which converts all 
> sorts of objects to POSIXct. I would expect this function to return 
> your desired format if you feed it with the numeric values that 
> locator() returned.
> Jannis
> On 07/29/2011 03:40 PM, cristabel.duran at waldbau.uni-freiburg.de wrote:
>> Dear R-list,
>> I have a plot with y-axis corresponding to wind measurments
>> and x-axis with date-time information.
>> When I want to identify some extrem wind events in the
>> wind-curve, I use locator() to get the exact
>> date-information, by clicking in the points in graph I´m
>> interested in.
>> I get in the R console the x and y coordinates.
>> The x coordinates are not in a POSIXct format, I guess R is
>> returning the x coordinates in a time unit as miliseconds
>> or something else.
>> Do anyone how to get the x coordinates directly in a
>> POSIXct format?
>> Thanks in advance!
>> Cristabel.
>> Cristabel Durán Rangel. PhD Student.
>> Institute of Silviculture. Faculty of Forest and
>> Environmental Sciences. University of Freiburg.
>> Germany
>> Telf: +49 (761) 203 8604 (ofc)
>> „Man lernt die Physiognomie einer Landschaft desto besser
>> kennen, je genauer man die einzelnen Züge auffaßt, sie
>> untereinander vergleicht und so auf dem Wege der Analysis
>> den Quellen der Genüsse nachgeht, die uns das große
>> Naturgemälde bietet.“
>>                 Alexander von Humboldt, 1799
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide 
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.

More information about the R-help mailing list