Update raster cells of files (on disk)
Update cell values of a file (i.e., cell values on disk) associated with a RasterLayer or RasterBrick.
User beware: this function _will_ make changes to your file (first make a copy if you are not sure what you are doing).
Writing starts at a cell number cell. You can write a vector of values (in cell order), or a matrix. You can also provide a vector of cell numbers (of the same length as vector v) to update individual cells.
See writeFormats for supported formats.
## S4 method for signature 'RasterLayer' update(object, v, cell, ...) ## S4 method for signature 'RasterBrick' update(object, v, cell, band, ...)
object |
RasterLayer or RasterBrick that is associated with a file |
v |
vector or matrix with new values |
cell |
cell from where to start writing. Or a vector of cell numbers if v is a vector of the same length |
.
band |
band (layer) to update (for RasterBrick objects) |
.
... |
additional arguments. None implemented |
RasterLayer or RasterBrick
## Not run: # setting up an example RasterLayer with file r <- raster(nrow=5, ncol=10, vals=0) r <- writeRaster(r, rasterTmpFile(), overwrite=TRUE, datatype='INT2S') as.matrix(r) # update with a vector starting a cell r <- update(r, v=rep(1, 5), cell=6) # 99.99 gets rounded because this is an integer file r <- update(r, v=9.99, cell=50) as.matrix(r) # update with a vector of values and matching vector of cell numbers r <- update(r, v=5:1, cell=c(5,15,25,35,45)) as.matrix(r) # updating with a marix, anchored at a cell number m <- matrix(1:10, ncol=2) r <- update(r, v=m, cell=2) as.matrix(r) ## End(Not run)
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