Dear all,
I have the following GDP data by latitude and longitude at 0.5 degree by
0.5 degree.
temp <- dput(head(ptsDF,10))
structure(list(longitude = c(-68.25, -67.75, -67.25, -68.25,
-67.75, -67.25, -71.25, -70.75, -69.25, -68.75), latitude = c(-54.75,
-54.75, -54.75, -54.25, -54.25, -54.25, -53.75, -53.75, -53.75,
-53.75), GDP = c(1.683046, 0.3212307, 0.0486207, 0.1223268, 0.0171909,
0.0062104, 0.22379, 0.1406729, 0.0030038, 0.0057422)), .Names
c("longitude",
"latitude", "GDP"), row.names = c(4L, 17L, 30L, 43L, 56L,
69L,
82L, 95L, 108L, 121L), class = "data.frame")
I would like to aggregate the data 1 degree by 1 degree. I understand that
the first step is to convert to raster. I have tried:
rasterDF <- rasterFromXYZ(temp)
r <- aggregate(rasterDF,fact=2, fun=sum)
But this does not seem to work. Could anyone help me out please? Thank you
in advance.
Sincerely,
Milu
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Milu, Perhaps an approach like this would work. In the example below, I calculate the mean GDP for each 1 degree by 1 degree. temp$long1 <- floor(temp$longitude) temp$lat1 <- floor(temp$latitude) temp1 <- aggregate(GDP ~ long1 + lat1, temp, mean) long1 lat1 GDP 1 -69 -55 0.90268640 2 -68 -55 0.09831317 3 -72 -54 0.22379000 4 -71 -54 0.14067290 5 -70 -54 0.00300380 6 -69 -54 0.00574220 Jean On Thu, Jul 21, 2016 at 3:57 PM, Miluji Sb <milujisb at gmail.com> wrote:> Dear all, > > I have the following GDP data by latitude and longitude at 0.5 degree by > 0.5 degree. > > temp <- dput(head(ptsDF,10)) > structure(list(longitude = c(-68.25, -67.75, -67.25, -68.25, > -67.75, -67.25, -71.25, -70.75, -69.25, -68.75), latitude = c(-54.75, > -54.75, -54.75, -54.25, -54.25, -54.25, -53.75, -53.75, -53.75, > -53.75), GDP = c(1.683046, 0.3212307, 0.0486207, 0.1223268, 0.0171909, > 0.0062104, 0.22379, 0.1406729, 0.0030038, 0.0057422)), .Names > c("longitude", > "latitude", "GDP"), row.names = c(4L, 17L, 30L, 43L, 56L, 69L, > 82L, 95L, 108L, 121L), class = "data.frame") > > I would like to aggregate the data 1 degree by 1 degree. I understand that > the first step is to convert to raster. I have tried: > > rasterDF <- rasterFromXYZ(temp) > r <- aggregate(rasterDF,fact=2, fun=sum) > > But this does not seem to work. Could anyone help me out please? Thank you > in advance. > > Sincerely, > > Milu > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. >[[alternative HTML version deleted]]
Dear Jean, Thank you so much for your reply and the solution, This does work. I was wondering is this similar to 'rasterFromXYZ'? Thanks again! Sincerely, Milu On Fri, Jul 22, 2016 at 3:06 PM, Adams, Jean <jvadams at usgs.gov> wrote:> Milu, > > Perhaps an approach like this would work. In the example below, I > calculate the mean GDP for each 1 degree by 1 degree. > > temp$long1 <- floor(temp$longitude) > temp$lat1 <- floor(temp$latitude) > temp1 <- aggregate(GDP ~ long1 + lat1, temp, mean) > > long1 lat1 GDP > 1 -69 -55 0.90268640 > 2 -68 -55 0.09831317 > 3 -72 -54 0.22379000 > 4 -71 -54 0.14067290 > 5 -70 -54 0.00300380 > 6 -69 -54 0.00574220 > > Jean > > On Thu, Jul 21, 2016 at 3:57 PM, Miluji Sb <milujisb at gmail.com> wrote: > >> Dear all, >> >> I have the following GDP data by latitude and longitude at 0.5 degree by >> 0.5 degree. >> >> temp <- dput(head(ptsDF,10)) >> structure(list(longitude = c(-68.25, -67.75, -67.25, -68.25, >> -67.75, -67.25, -71.25, -70.75, -69.25, -68.75), latitude = c(-54.75, >> -54.75, -54.75, -54.25, -54.25, -54.25, -53.75, -53.75, -53.75, >> -53.75), GDP = c(1.683046, 0.3212307, 0.0486207, 0.1223268, 0.0171909, >> 0.0062104, 0.22379, 0.1406729, 0.0030038, 0.0057422)), .Names >> c("longitude", >> "latitude", "GDP"), row.names = c(4L, 17L, 30L, 43L, 56L, 69L, >> 82L, 95L, 108L, 121L), class = "data.frame") >> >> I would like to aggregate the data 1 degree by 1 degree. I understand that >> the first step is to convert to raster. I have tried: >> >> rasterDF <- rasterFromXYZ(temp) >> r <- aggregate(rasterDF,fact=2, fun=sum) >> >> But this does not seem to work. Could anyone help me out please? Thank you >> in advance. >> >> Sincerely, >> >> Milu >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> > >[[alternative HTML version deleted]]