Tract {sampSurf} | R Documentation |
Tract
"
This generic function has methods based on the signature
formal argument object
. It is used as a constructor function for
objects that are of class "Tract
". This method
should be used in preference to new
to insure a valid
object.
Tract(object, ...)
object |
This is the signature formal argument, see the methods for more details. |
... |
Formal arguments that are different for each method, see those for details. |
There is no default generic function for Tract
per
se. It is defined completely with respect to the signature of its
methods Tract-methods
. Methods are available for several
useful signatures, such as objects of class
"RasterLayer"
, allowing for a large variety of ways
to generate objects of this class. Other methods can obviously be added
for other signatures as necessary.
A valid object of class "Tract
."
Jeffrey H. Gove
tract = Tract(c(x=20,y=20), cellSize=0.25) #extents constructor tr = Tract(,0.5, c(x=20,y=20),c(0.25,0.25),units='metric') #missing constructor tr2 = Tract(cellSize=0.5, cellDims=c(x=20,y=20), cellCenter=c(0.25,0.25), units='metric') #same constructor as the previous tr.ext = Tract(c(x=10,y=15), cellSize=0.5) #maximal extent constructor #bounding box constructor... bb = bbox(tr.ext) bb[,1] = c(5,4) tr3 = Tract(bb, 0.5) #RasterLayer constructor... ex = extent(tr3) rl = raster(ex, nrow=10, ncols=10, crs=NA) ## Not run: tr4 = Tract(rl) #error: non-square grid cells ## End(Not run) rl = raster(ex, nrow=22, ncol=10, crs=NA) tr4 = Tract(rl) #okay, square cells