Re: [R] from long/lat to UTM
On 10-Mar-05 Sander Oom wrote: Hi Yyan, The proj4R package by Roger Bivand will allow you to project data in many ways and directions. http://spatial.nhh.no/R/Devel/proj4R-pkg.pdf It uses the proj libraries from: http://www.remotesensing.org/proj/ Not sure where you would derive the time zone! Good luck, Sander. While there is a longitude-based nominal time-zone structure (0deg E is the centre of Zone 0 which extends for 7.5deg either side; successive time-zones move round by 15deg), this does not apply cleanly to the time-shifts adopted in different places for local time. A World map of regions with different local-time offsets is a crazy patchwork, with all sorts of contradictory looking regions. For instance, the -0700 region of the USA extends from approx -0830 to approx -0620, covering over 2 hours, and parts of -0800 touch the -0700 line and are more than 0100 East of parts of -0700. Even worse can be found over the Indian/Central Asian and Malaysian parts of the world, where time-shifts of 30 miniutes are also frequent (and, according to my Atlas, one country, Nepal, has 52/3 i.e. +0540!). As Sander says, Not sure where you would derive the time zone!. Unless you can refer a (long,lat) position to a look-up table, you can't predict what the zone will be to less the 1 hour (except of course for the nominal time-zones by 15deg sectors). I've never encountered a digital version of such a table (my Atlas must be based on one, though). Best wishes, Ted. yyan liu wrote: Hi: Is there any function in R which can convert the long/lat to UTM(Universal Transverse Mercator)? There are quite a few converters on Internet. However, the interface is designed as input-output which I can not convert lots of locations at the same time. Another question is whether there is a function in R which can tell the time zone from the location's lat/long? Thank you! liu __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- Dr. Sander P. Oom Animal, Plant and Environmental Sciences, University of the Witwatersrand Private Bag 3, Wits 2050, South Africa Tel (work) +27 (0)11 717 64 04 Tel (home) +27 (0)18 297 44 51 Fax +27 (0)18 299 24 64 Email [EMAIL PROTECTED] Web www.oomvanlieshout.net/sander __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html E-Mail: (Ted Harding) [EMAIL PROTECTED] Fax-to-email: +44 (0)870 094 0861 Date: 10-Mar-05 Time: 09:47:25 -- XFMail -- __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] from long/lat to UTM
Ted.Harding at nessie.mcc.ac.uk writes: : : yyan liu wrote: : Hi: :Is there any function in R which can convert the : long/lat to UTM(Universal Transverse Mercator)? :There are quite a few converters on Internet. : However, the interface is designed as input-output : which I can not convert lots of locations at the same : time. :Another question is whether there is a function in R : which can tell the time zone from the location's : lat/long? :Thank you! : : liu : : On 10-Mar-05 Sander Oom wrote: : Hi Yyan, : : The proj4R package by Roger Bivand will allow you to project data in : many ways and directions. : : http://spatial.nhh.no/R/Devel/proj4R-pkg.pdf : : It uses the proj libraries from: : : http://www.remotesensing.org/proj/ : : Not sure where you would derive the time zone! : : Good luck, : : Sander. : : While there is a longitude-based nominal time-zone : structure (0deg E is the centre of Zone 0 which extends : for 7.5deg either side; successive time-zones move round : by 15deg), this does not apply cleanly to the time-shifts : adopted in different places for local time. : : A World map of regions with different local-time offsets : is a crazy patchwork, with all sorts of contradictory : looking regions. For instance, the -0700 region of : the USA extends from approx -0830 to approx -0620, : covering over 2 hours, and parts of -0800 touch the : -0700 line and are more than 0100 East of parts of -0700. : Even worse can be found over the Indian/Central Asian : and Malaysian parts of the world, where time-shifts : of 30 miniutes are also frequent (and, according to my : Atlas, one country, Nepal, has 52/3 i.e. +0540!). : : As Sander says, Not sure where you would derive the time zone!. : : Unless you can refer a (long,lat) position to a look-up : table, you can't predict what the zone will be to less : the 1 hour (except of course for the nominal time-zones : by 15deg sectors). I've never encountered a digital : version of such a table (my Atlas must be based on one, : though). : : Best wishes, : Ted. The fBasics package of the rmetrics project uses the Olsen time zone data base which does take some of these things into account. __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] from long/lat to UTM
On 10-Mar-05 Gabor Grothendieck wrote: Ted.Harding at nessie.mcc.ac.uk writes: : [...] : As Sander says, Not sure where you would derive the time zone!. : : Unless you can refer a (long,lat) position to a look-up : table, you can't predict what the zone will be to less : the 1 hour (except of course for the nominal time-zones : by 15deg sectors). I've never encountered a digital : version of such a table (my Atlas must be based on one, : though). : : Best wishes, : Ted. The fBasics package of the rmetrics project uses the Olsen time zone data base which does take some of these things into account. Thanks, Gabor! However, this seems to be just the usual sort of thing -- TimeZone name with corresponding TZ data. You first have to know the TZ name. (Unless I have overlooked sonething in the Olsen database). What I had in mind was a look-up facility whereby a (long,lat) pair could be submitted as a query, returning the TZ region (name) within which that geographical point lay. The only completely general mechanism I can think of would consist of a) a named list of boundary contours b) a function which, for each name in the list, returns the TZ name Then, for instance, given a point P = (long,lat), the list could be searched by verifying, for each contour in the list, whether the point lay in the region circumscribed by the coutour (e.g. by computing the winding number for the contour with respect to the point). This would also work for regions with holes in them, provided the boundary of the hole was presented in the correct order of points (e.g. such that the region of which it was the boundary lies to the left as you go through the sequence). If, for instance, I had the contour data for the TZ map in my Atlas, I could construct such a thing! But, as I say, I have not come across such a dataset. I'd be interested to learn of one, though! Best wishes, Ted. E-Mail: (Ted Harding) [EMAIL PROTECTED] Fax-to-email: +44 (0)870 094 0861 Date: 10-Mar-05 Time: 16:13:01 -- XFMail -- __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] from long/lat to UTM
Ted Harding [EMAIL PROTECTED] 03/10/05 09:13AM
On 10-Mar-05 Gabor Grothendieck wrote:
Ted.Harding at nessie.mcc.ac.uk writes:
: [...]
: As Sander says, Not sure where you would derive the time
zone!.
:
[snip]
The only completely general mechanism I can think of would
consist of
a) a named list of boundary contours
I found a shapefile of time zones at:
http://openmap.bbn.com/data/shape/timezone/
A google search on the keywords timezone shapefile finds a
few other possibilities.
b) a function which, for each name in the list, returns
the TZ name
The maptools package can read in the above shapefile and
convert it to a list of polygons and the sgeostat has an
in.polygon function to see if a point is in a given polygon.
The following code worked for me:
library(maptools)
tz - read.shape('c:/maps/WrldTZA')
plot(tz)
plot(tz,xlim=c(-150,-50), ylim=c(20,50))
mappoly - Map2poly(tz)
library(sgeostat)
tmp - sapply(mappoly, function(x){ x - na.exclude(x)
in.polygon( -110, 42, x[,1], x[,2] ) } )
tz$att.data[tmp,]
the -110 and 42 come from me plotting the map and using
locator to approximate where I am at. I was actually
suprized at how quick the sapply was (under a second on
my fairly fast pc (windows 2000)).
It shouldn't be too hard to convert this into a more general
function.
Greg Snow, Ph.D.
Statistical Data Center
[EMAIL PROTECTED]
(801) 408-8111
__
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Re: [R] from long/lat to UTM
On 10-Mar-05 Greg Snow wrote: [...] I found a shapefile of time zones at: http://openmap.bbn.com/data/shape/timezone/ A google search on the keywords timezone shapefile finds a few other possibilities. b) a function which, for each name in the list, returns the TZ name The maptools package can read in the above shapefile and convert it to a list of polygons and the sgeostat has an in.polygon function to see if a point is in a given polygon. The following code worked for me: [] Many thanks, Greg. That looks just the job, and I'll look into it. All best wishes, Ted. E-Mail: (Ted Harding) [EMAIL PROTECTED] Fax-to-email: +44 (0)870 094 0861 Date: 10-Mar-05 Time: 18:10:23 -- XFMail -- __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
RE: [R] from long/lat to UTM
I think I recall seeing a limited capability in the PBSmapping package. Tom -Original Message- From: yyan liu [mailto:[EMAIL PROTECTED] Sent: Wednesday, 9 March 2005 1:20 PM To: r-help@stat.math.ethz.ch Subject: [R] from long/lat to UTM Hi: Is there any function in R which can convert the long/lat to UTM(Universal Transverse Mercator)? There are quite a few converters on Internet. However, the interface is designed as input-output which I can not convert lots of locations at the same time. Another question is whether there is a function in R which can tell the time zone from the location's lat/long? Thank you! liu __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] from long/lat to UTM
Hi Yyan, The proj4R package by Roger Bivand will allow you to project data in many ways and directions. http://spatial.nhh.no/R/Devel/proj4R-pkg.pdf It uses the proj libraries from: http://www.remotesensing.org/proj/ Not sure where you would derive the time zone! Good luck, Sander. yyan liu wrote: Hi: Is there any function in R which can convert the long/lat to UTM(Universal Transverse Mercator)? There are quite a few converters on Internet. However, the interface is designed as input-output which I can not convert lots of locations at the same time. Another question is whether there is a function in R which can tell the time zone from the location's lat/long? Thank you! liu __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- Dr. Sander P. Oom Animal, Plant and Environmental Sciences, University of the Witwatersrand Private Bag 3, Wits 2050, South Africa Tel (work) +27 (0)11 717 64 04 Tel (home) +27 (0)18 297 44 51 Fax +27 (0)18 299 24 64 Email [EMAIL PROTECTED] Web www.oomvanlieshout.net/sander __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
[R] from long/lat to UTM
Hi: Is there any function in R which can convert the long/lat to UTM(Universal Transverse Mercator)? There are quite a few converters on Internet. However, the interface is designed as input-output which I can not convert lots of locations at the same time. Another question is whether there is a function in R which can tell the time zone from the location's lat/long? Thank you! liu __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
