Description Usage Arguments Details Value See Also Examples
Calculate spectral indices (e.g. NDVI, tasseled cap coefficients etc.) from
multispectral data. Calculations are based on the functions
spectralIndices
and
tasseledCap
. Refer to the documentation of these
functions for more details.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | calcIndices(
x,
indices = "NDVI",
sat = NULL,
blue = NULL,
green = NULL,
red = NULL,
nir = NULL,
swir1 = NULL,
swir2 = NULL,
swir3 = NULL,
coefs = list(L = 0.5, G = 2.5, L_evi = 1, C1 = 6, C2 = 7.5, s = 1, swir2ccc = NULL,
swir2coc = NULL),
filename = "",
par = FALSE,
threads = 2,
m = 2,
progress = TRUE,
...
)
|
x |
Raster* or SpatialPointsDataFrame object or list of Raster* or SpatialPointsDataFrame objects. |
indices |
Character vector indicating Which indices are calculated.
Tasseled Cap indices are abbreviated as |
sat |
Character. If calculating tasseled cap indices, name of the sensor
needs to be provided. One of: c("Landsat4TM", "Landsat5TM", "Landsat7ETM",
"Landsat8OLI", "MODIS", "QuickBird", "Spot5", "RapidEye"). See
|
blue |
Integer. Blue band. |
green |
Integer. Green band. |
red |
Integer. Red band. |
nir |
Integer. Near infrared band (700-1100 nm). |
swir1 |
temporarily deprecated |
swir2 |
Integer. Shortwave infrared band (1400-1800 nm) |
swir3 |
Integer. Shortwave infrared band (2000-2500 nm) |
coefs |
Coefficients necessary to calculate some of the spectral indices
(e.g. EVI). See |
filename |
Character. Output file name including path to directory and
eventually extension. If |
par |
Logical. Should the function be executed on parallel threads |
threads |
Number of parallel threads used if par = TRUE |
m |
tuning parameter to determine how many blocks will be used (m blocks will be processed by each cluster) |
progress |
Logical. If TRUE (default) a progress bar is displayed when using parallel processing. |
... |
Other arguments passed to |
If x is a Raster* or list of Raster* objects, each layer should be one of the
spectral bands used to calculate the indices. If x is a SpatialPointsDataFrame
or list of spatialPointsDataFrame, each column should be a spectral band. When
calculating tasseledCap indices, bands should be provided in a specific order
specified in tasseledCap
.
Tasseled Cap Angle (TCA) and Distance (TCD) are calculated from greenness (TCG) and brightness (TCB) as follows:
TCA = \arctan(\frac{TCG}{TCB})
TCD = √{TCB^{2} + TCG^{2}}
If x
is a list of Raster* objects, the processing can be parallelized
using cluster
. In that case the user has to set
par = TRUE
and provide the number of parallel threads threads
.
You can control how many blocks will be processed by each thread by setting
m
(see cluster
).
Raster* or SpatialPointsDataFrame object or list of Raster* or SpatialPointsDataFrame objects.
spectralIndices
,
tasseledCap
, cluster
1 2 3 4 5 6 7 8 9 10 11 | library(raster)
# Open Landsat BAP image
BAP_2006 <- stack(system.file("extdata/examples/Landsat_BAP_2006.tif",package =
"foster"))
# Calculate NDVI
VI_2006 <- calcIndices(BAP_2006,
indices = "NDVI",
red=3,
nir=4)
|
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