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For developers: Hidden fasterRaster functions

Adam B. Smith

2024-10-24

Source: vignettes/hidden_functions.Rmd
hidden_functions.Rmd

fasterRaster contains a set of “private” functions that users can access using fasterRaster:::functionName. These functions are useful for power users and developers. Not all hidden functions are listed here. Often, a method will have a hidden function of the same name that starts with a period (e.g., .plot()). This “period” function is intended to be supplied the sources() name of a GRaster or GVector from other functions so that the calling function does not need to spend the time creating the GRaster or GVector pointer before calling the function. “Period” functions will, though, often work on GRasters or GVectors, though some error-checking and region re-definition is not conducted.

General

  • .addLocationProject(): Add a “location” or “project” argument to a list to be passed to [rgrass::execGRASS()]
  • .backdoor(): Calls [faster()] and sets GRASS folder to “C:/Program Files/GRASS GIS X.Y”, plus other options useful for development.
  • .fileExt(): Get file extension
  • .ls(): Lists the sources of all objects in the active GRASS “project/location”
  • .message(): Display a warning or message if the given warning has not been displayed since fasterRaster was attached or if a given number of hours has passed
  • .quiet(): Returns “quiet” if faster("verbose") is TRUE
  • .workDir(): Working directory of a GLocation object

Rasters and vectors

  • .copyGSpatial(): Make a copy of the GRASS file pointed to by a GRaster or GVector
  • .exists(): Does the GRASS file of a GRaster or GVector exist?
  • .ext(): Extent from the sources() name of a GRaster or GVector
  • .makeSourceNames(): Makes one or more statistically unique strings that can be used as file names to represent rasters or vectors in GRASS
  • .plot(): Plot using the sources() name of a GRaster or GVector
  • .projection(): Value of the @projection slot in a GRaster or GVector
  • .rastInfo() and .vectInfo(): Metadata for a GRASS raster or vector
  • .rename(): Rename a GRASS raster or vector
  • .rm(): Delete rasters or vectors in GRASS

Vectors

  • .aggDisaggVect(): Aggregate or disaggregate a vector using its sources() name.
  • .geomtype(): Geometry type (“point”, “line”, or “area”) from the sources() name of a GVector
  • .validVector(): Test if a GVector is valid.
  • .vAsDataTable(): Convert the attribute table linked to a vector in GRASS to a data.table. This table is distinct from the attribute table attached to a GVector
  • .vAttachDatabase(): Add a database table to the GRASS representation of a GVector
  • .vCats(): Get a data.table with a single column named cat, which corresponds to the GRASS attribute table’s cat column
  • .vDetachDatabase(): Detach the GRASS database from a GRASS vector
  • .vHasDatabase(): Tests if GRASS vector has a database
  • .vIncrementCats(): Increment category values of a GVector
  • .vNames(): “GRASS” vector attribute table column names
  • .vRecat(): Change GRASS category indices of a GRASS vector
  • .vValidCats(): Are category values of a vector valid?

Rasters

  • .layerIndex(): Gets the index of GRaster layers from a numeric, integer, character, or logical vector
  • .makeGRaster() and .makeGVector(): Make GRasters or GVectors from a vector of sources, which are pointers to files in GRASS
  • .minVal() and .maxVal(): Values in the @minVal and @maxVal slots in a GRaster
  • .nlevels(): Number of levels in a SpatVector, data.frame, data.table, empty string, or a list of data.frames, data.tables, and/or empty strings.

GRAS “Projects” (“locations”) and “mapsets”

  • .locationCreate() Make a connection to GRASS (i.e., start GRASS from within R) and create a location
  • .locationDelete() Deletes all files associated with a GRASS “location” and mapset
  • .locationFind(): Find a specific GRASS “location” that already exists
  • .locationRestore() Reconnect GRASS to a previously-created GRASS “location”
  • .locations(): List of all available “locations”
  • .mapset(): GRASS “mapset” of an object or the active session

GRASS “regions”

  • .region(): Change or report the active region’s extent and resolution
  • .regionDim()]: Change or report the active region’s resolution (also dim() and related functions, with no arguments)
  • .regionExt(): Change or report the active region’s extent (also ext() and related functions, with no arguments)
  • .regionRes(): Change or report the active region’s dimensions (also res() and related functions, with no arguments)

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