| ReadVI3g {greenbrown} | R Documentation |
This function reads GIMMS VI3g binary files, pre-processes the values (exclusion of flagged values, subset for area of interest) and returns the result as a raster layer. The function can be used to read the original GIMMS NDVI3g data files to R.
ReadVI3g(file, flag = 2:7, ext = c(-180, 180, -90, 90))
file |
GIMMS VI3g file name |
flag |
vector of quality flags that should be excluded. Default: 2:7 (all values with reduced quality excluded). If you want to keep all values set |
ext |
extent (xmin, xmax, ymin, ymax) for which to extract the data |
The GIMMS NDVI3g dataset comes with the following quality flags:
FLAG = 1 (Good value)
FLAG = 2 (Good value, possibly snow)
FLAG = 3 (NDVI retrieved from spline interpolation)
FLAG = 4 (NDVI retrieved from spline interpolation, possibly snow)
FLAG = 5 (NDVI retrieved from average seasonal profile)
FLAG = 6 (NDVI retrieved from average seasonal profile, possibly snow)
FLAG = 7 (missing data)
raster layer
Matthias Forkel <matthias.forkel@geo.tuwien.ac.at> [aut, cre]
# data <- ReadVI3g("geo00oct15a.n14-VI3g")
# plot(data)