[R-sig-Geo] plotKML and time stamp

[Struve,Juliane]

Hello,

The attribute I am interested in is a site number. When I use the site number as attribute data the size of the bubble is proportional to the number, which does not really make sense given that the data are just site numbers. But when I make it a constant I lose the site number information. How can I get a plot that shows all the locations with the same size bubble but displays also the site number information, say like a label ? It seems that the attribute data need to be numeric.

Thank you for your time,

Juliane

-----Original Message-----
From: Edzer Pebesma [mailto:edzer.pebesma at uni-muenster.de] 
Sent: Monday, October 01, 2012 4:55 PM
To: Struve,Juliane; r-sig-geo at r-project.org
Subject: Re: [R-sig-Geo] plotKML and time stamp



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
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> 

--
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