Description Usage Arguments Details Value Author(s) See Also Examples
Get MODIS tile id(s) for a geographic area.
1 |
tileH |
Integer. Horizontal tile number(s) (between 0 and 35). I.e.: |
tileV |
Integer. Vertical tile number(s) (between 0 and 17). I.e.: |
extent |
Extent Informations see details. |
buffer |
Numeric [map units]. Buffers the extent, negative values are allowed. If |
system |
Character. Default is |
zoom |
Logical, default |
extent : |
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If "list": | |
Then LatLon coordinates in the following form: | |
list(xmin=mumeric, xmax=mumeric, ymax=mumeric, ymin=mumeric) . |
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If "character": | |
the country name of a map object (see package maps ), you can use ?search4map to find a map by regular expression. |
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Or the file name (plus path) of a raster* or a ESRI Shapefile (shp). | |
Other: | |
If "rasterLayer","rasterStack" or "rasterBrick" (package raster). |
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Using a raster* object as "extent", the function determines the "extent", "resolution", and the "projection" from that raster*. This will be used by "runGdal" creating perfectly matching files. If the raster file has not a valid CRS string it assumes LatLon!) | |
Using an "extent" (package raster) object, it must be in LatLon, as the extent object has no projection information attached. |
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If ESRI shapefile (shp) or maps:::map object, a call to sp:::over is performed to determine MODIS tile containg the "extent", this often considerably reduces the number of required tiles but can lead to NO-DATA areas if in the bounding box of 'extent' not all tiles had to be downloaded!
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PS:
If an extent is specified through tileV, tileH
arguments, no cropping is performed and the full un-cutted tile(s) (if more than one then also mosaicked) is/are processed!
List
Matteo Mattiuzzi
raster package: ?extent,?raster,?stack,?brick
or ?shapefile
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 | ## Not run:
# ex 1 ############
# drawing the extent. NOTE: It is not possible to draw a date-line crossing area!
# draw extent with zoom, for smaller extents
getTile()
# ex 2 ############
# "extent" specified with a vector file (map or shp)
japan <- getTile(extent="Japan")
japan
# and here the same "extent" using the bounding box
getTile(extent=japan$extent)
# ex 3 ############
# with tileH and tileV
getTile(tileH=18:19,tileV=4)
# ex 4 ############
# with extent of class "list"
Austria <- list(ymin=46.12,ymax=49.3,xmin=9.2,xmax=17.47)
getTile(extent=Austria)
getTile(extent=Austria,buffer=10)
getTile(extent=Austria,buffer=c(0,10))
# ex 5 ############
# with extent or raster* object from raster package
# rasterObject
rasterObject <- raster(xmn=9.2,xmx=17.47,ymn=46.12,ymx=49.3)
getTile(extent=rasterObject)
# raster extent
ext <- extent(rasterObject)
getTile(extent=ext)
# rasterObject in UTM33N
CRS <- "+proj=utm +zone=33 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"
rasterObject <- projectExtent(rasterObject,CRS)
extent(rasterObject)
projection(rasterObject)
getTile(extent=rasterObject)
# ex 6 #################
require(mapdata)
# Character name of a map contained in "map("worldHires",extent,plot=FALSE)".
# Use with caution! The following example includes much more areas than the main USA.
map("worldHires","usa")
# Maybe before using this option run a test map("worldHires",yourCharacterExtent).
# Check awailability of maps with:
map("worldHires",plot=FALSE)$names
# or
search4map("Gua")
getTile(extent="usa")
# it is also possible to put an map object. In this specific example the low resolution map is used!
# in such case polygon matching is used see ex 2
getTile(extent=map("usa",plot=FALSE))
# also possible:
ext <- map("state", region = c("new york", "new jersey", "penn"))
getTile(extent=ext)
# or:
getTile(extent=c("austria","germany","switzerland"))
# SRTM data
getTile(extent=c("austria","germany","switzerland"),system="SRTM")
## End(Not run)
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