Jonsson
2013-Jan-27 13:53 UTC
[R] how to extract values from a raster according to Lat and long of the values?
having 12 files with 12 hdrs for one year: these files are raster
(projected WGS84,lat
long):https://echange-fichiers.inra.fr/get?k=rLSyoavrnifGyH5XrlO
samples = 1440
lines = 720
bands = 1
header offset = 0
file type = ENVI Standard
data type = 4
interleave = bsq
byte order = 0
map info = { Geographic Lat/Lon, 1, 1, -180, 90, 0.25,
0.25,WGS-84}
coordinate system string
GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",
SPHEROID["WGS_1984",6378137,298.257223563]]
,PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
}
These lines will open the files as a list:
a<-list.files("D:\\ECV\\2010", "*.envi",
full.names = TRUE)
for(i in 1:length(a)){
d <- raster(a[i]}
I would like to extract the values correspond to 44.8386? N, 0.5783? W from
all files as txt file
--
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Pascal Oettli
2013-Jan-28 02:15 UTC
[R] how to extract values from a raster according to Lat and long of the values?
?extract HTH Pascal Le 27/01/2013 22:53, Jonsson a ?crit :> having 12 files with 12 hdrs for one year: these files are raster > (projected WGS84,lat > long):https://echange-fichiers.inra.fr/get?k=rLSyoavrnifGyH5XrlO > > samples = 1440 > lines = 720 > bands = 1 > header offset = 0 > file type = ENVI Standard > data type = 4 > interleave = bsq > byte order = 0 > map info = { Geographic Lat/Lon, 1, 1, -180, 90, 0.25, > 0.25,WGS-84} > coordinate system string > GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984", > SPHEROID["WGS_1984",6378137,298.257223563]] > ,PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]] > } > These lines will open the files as a list: > > a<-list.files("D:\\ECV\\2010", "*.envi", full.names = TRUE) > for(i in 1:length(a)){ > d <- raster(a[i]} > > I would like to extract the values correspond to 44.8386? N, 0.5783? W from > all files as txt file > > > > -- > View this message in context: http://r.789695.n4.nabble.com/how-to-extract-values-from-a-raster-according-to-Lat-and-long-of-the-values-tp4656767.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. >
jim holtman
2013-Jan-28 02:50 UTC
[R] how to extract values from a raster according to Lat and long of the values?
How do you get those values from the example header file that you included? On Sun, Jan 27, 2013 at 9:15 PM, Pascal Oettli <kridox at ymail.com> wrote:> ?extract > > HTH > Pascal > > > Le 27/01/2013 22:53, Jonsson a ?crit : >> >> having 12 files with 12 hdrs for one year: these files are raster >> (projected WGS84,lat >> long):https://echange-fichiers.inra.fr/get?k=rLSyoavrnifGyH5XrlO >> >> samples = 1440 >> lines = 720 >> bands = 1 >> header offset = 0 >> file type = ENVI Standard >> data type = 4 >> interleave = bsq >> byte order = 0 >> map info = { Geographic Lat/Lon, 1, 1, -180, 90, 0.25, >> 0.25,WGS-84} >> coordinate system string >> GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984", >> SPHEROID["WGS_1984",6378137,298.257223563]] >> ,PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]] >> } >> These lines will open the files as a list: >> >> a<-list.files("D:\\ECV\\2010", "*.envi", full.names = TRUE) >> for(i in 1:length(a)){ >> d <- raster(a[i]} >> >> I would like to extract the values correspond to 44.8386? N, 0.5783? W >> from >> all files as txt file >> >> >> >> -- >> View this message in context: >> http://r.789695.n4.nabble.com/how-to-extract-values-from-a-raster-according-to-Lat-and-long-of-the-values-tp4656767.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> 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. >> > > ______________________________________________ > 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.-- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it.
Jonsson
2013-Jan-28 11:33 UTC
[R] how to extract values from a raster according to Lat and long of the values?
jholtman: I do not understand you question? -- View this message in context: http://r.789695.n4.nabble.com/how-to-extract-values-from-a-raster-according-to-Lat-and-long-of-the-values-tp4656767p4656847.html Sent from the R help mailing list archive at Nabble.com.
Jonsson
2013-Jan-28 11:35 UTC
[R] how to extract values from a raster according to Lat and long of the values?
extract will extract values if you provide the x , y but then who to know which lat and long correspond to which x and y -- View this message in context: http://r.789695.n4.nabble.com/how-to-extract-values-from-a-raster-according-to-Lat-and-long-of-the-values-tp4656767p4656848.html Sent from the R help mailing list archive at Nabble.com.