[R-sig-Geo] Aggregate data to lower resolution

[Miluji Sb]

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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