These are helper functions for programmers and for debugging that provide information about whether a Raster object has associated values, and if these are in memory or on disk.
fromDisk is TRUE if the data source is a file on disk; and FALSE if the object only exists in memory.
inMemoryi is TRUE if all values are currently in memory (RAM); and FALSE if not (in which case they either are on disk, or there are no values).
hasValues is TRUE if the object has cell values.
fromDisk(x)## S4 method for signature 'BasicRaster'inMemory(x)## S4 method for signature 'BasicRaster'hasValues(x)