[R-sig-Geo] plotKML and time stamp

[Edzer Pebesma]

On 10/01/2012 05:47 PM, Struve,Juliane wrote:
> Edzer,
> 
> Thank you for your help, this works nicely. When xy.sp are the points and tc is the date/time stamp, why is df needed  ? 
> 

You can create an STI object with just the space-time points, leaving
out the df, but plotKML does not (yet) have a method to display STI
objects -- it wants STIDF with attributes. To work around this, you
could try giving the attribute a constant value, if you don't have sth
that varies.

> Regards,
> 
> Juliane 
> 
> 
> -----Original Message-----
> From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-project.org] On Behalf Of Edzer Pebesma
> Sent: Sunday, September 30, 2012 6:06 AM
> To: r-sig-geo at r-project.org
> Subject: Re: [R-sig-Geo] plotKML and time stamp
> 
> Juliane, try
> 
> xc = round(runif(10,-1,1)+27.2, 2)
> yc = round(runif(10,-1,1)+-82.5, 2)
> xy = cbind(xc, yc)
> tc = Sys.time() + 3600 * (1:10)
> df = data.frame(z1 = round(5 + rnorm(10), 2), z2 = 20:29)
> 
> library(sp)
> xy.sp = SpatialPoints(xy)
> proj4string(xy.sp) = CRS("+proj=longlat +datum=WGS84")
> 
> library(spacetime)
> ST = STIDF(xy.sp, tc, df)
> 
> library(plotKML)
> plotKML(ST)
> 
> see also
> 
> vignette(spacetime)
> 
> 
> On 09/30/2012 03:39 AM, Struve,Juliane wrote:
>> Dear list,
>>
>> After plotting this toy example on Google Earth I would like to add a date/time stamp to it so that the locations will be shown in sequence using the time slider. I am not quite sure how to approach this, can I add a date/time to my spatial points and then submit it to plotKML ? What format does the date/time stamp have to be in to be plotted on Google Earth ?
>>
>> Many thanks for any suggestions.
>>
>> Regards,
>>
>> Juliane
>>
>>
>> xc = round(runif(10,-1,1)+27.2, 2)
>> yc = round(runif(10,-1,1)+-82.5, 2)
>> xy = cbind(xc, yc)
>> xy.sp = SpatialPoints(xy)
>> df = data.frame(z1 = round(5 + rnorm(10), 2), z2 = 20:29) SP.spdf = 
>> SpatialPointsDataFrame(xy.sp, df)
>> plot(SP.spdf)
>> #add a projection
>> proj4string(SP.spdf) = CRS("+proj=longlat +datum=WGS84") 
>> plotKML(SP.spdf,kmz = FALSE)
>>
>> 	[[alternative HTML version deleted]]
>>
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>>
> 
> --
> Edzer Pebesma
> Institute for Geoinformatics (ifgi), University of Münster Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de
> http://www.52north.org/geostatistics      e.pebesma at wwu.de
> 
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at r-project.org
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> 

-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de
http://www.52north.org/geostatistics      e.pebesma at wwu.de