pointtobuffer: Point to buffer
In ndvits: NDVI Time series extraction and analysis

Description Usage Arguments Details Value Author(s) See Also Examples

Create a shapefile of points around the points given in the kml/shapefile.

1	pointtobuffer(shapefile, shapedir, ndvidirectory, region, Ystart, shapeext="shp", outshape = "buffer", outdir = ".", rad = 1, type="VITO_CLIP")

`shapefile`	name of the shape/kml file with multi-points from where the buffer is created. For a shapefile called ‘name.shp’ , `shapefile`="name". For a kml file, write the name of the layer.
`shapedir`	path to the shape/kml file. For a shapefile, `shapedir` is the path to the folder containing the shapefile. For example if the directory of the shapefile is ‘C:/Dir/name.shp’, `shapefile`="C:/Dir/". For a kml file, `shapedir` is the full directory of the kml file. For example `shapefile`="C:/Dir/name.kml". Please note that paths to files in R can be specified with either "/" or "\\" in Windows OS and "/" in UNIX OS.
`ndvidirectory`	path to the ndvi images folder (GeoTIFF files). Please note that paths to files in R can be specified with either "/" or "\\" in Windows OS and with "/" in UNIX OS.
`region`	name of the region, same as in the name of the ndvi images. Please refer to details section for more information on the nomenclature.
`Ystart`	starting year of the analysis (in four-digit format).
`shapeext`	extension of the shape/kml file : "shp" for a Esri shapefile or "kml" for a kml file from Google earth . By default, `shapeext` = "shp".
`outshape`	name of the new shapefile where the buffer is saved. By default, `outshape` = "buffer".
`outdir`	path to the folder where the new shapefile is saved. By default, `outdir` = ".".
`rad`	radius, maximum distance in pixels. New points are added to the shapefile if the distance to the points is smaller than `rad`. By default, `rad`=1, 8 points will be added around each points in the given shapefile.
`type`	type of nomenclature followed by the NDVI images : "VITO_CLIP", "VITO_VGT" or "GIMMS" (see details for more information). By default, `type` = "VITO_CLIP".

More about the variable type :
type = GIMMS : nomenclature from Global Land Cover Facility
[RE][YY][MMM][DDD].[SAT]-VIg.tif

RE : identifies the continent (AF for Africa,AZ for Australia and New Zealand, EA for Eurasia, NA for North America and SA for South America and Central America)
YY : the two last digits of the year
MMM : three-letter abbreviation of the month
DDD : identifies the composite period, 15a denotes the days 1-15 of the month, and 15b denotes the days from 16 to the end of the month.
SAT : identifies the satellite, NOAA-7, 9, 11, 14, 16, or 17 from which the data originated.

type = VITO_VGT : FreeVGT VITO's nomenclature
NDV_[YYYYMMDD]_[REGION]_Extract.tif

YYYY : identifies the year (four digits)
MM : identifies the months (two digits)
DD : identifies the date of the period : "01", "11" or "21" (10-day composite).
REGION : idendifies the region selected while extracting maps

type = VITO_CLIP : nomenclature after clipping the images in a particular region.
[REGION][YYYY]M[MM]P[D].tif

REGION : the region as entered while clipping data.
YYYY : identifies the year (four digits)
MM : identifies the months (two digits)
D : identifies the period (0, 1 or 2).

Nothing is return, a shapefile is created and saved in the folder outdir, under the name outshape.

Romain Frelat and Bruno Gerard

polytopoints

#local variables
shape="SLP_Mzimba"
shapedir=paste(system.file("extdata/shape", package="ndvits"),
    "/", sep="")
ndvidirectory=paste(system.file("extdata/VITO_Mzimba",
    package="ndvits"), "/", sep="")
region="Mzimba"
Ystart=2004
newshape="BufferMzimba"
dirshape="."
#the shapefile will be saved in the current directory.

pointtobuffer(shape, shapedir, ndvidirectory, region, Ystart,
   outshape = newshape, outdir = dirshape)