rpostgis (version 1.4.3)

pgGetRast: Load raster from PostGIS database.

Description

Retrieve rasters from a PostGIS table.

Usage

pgGetRast(
  conn,
  name,
  rast = "rast",
  bands = 1,
  boundary = NULL,
  clauses = NULL
)

Value

RasterLayer

Arguments

conn

A connection object to a PostgreSQL database

name

A character string specifying a PostgreSQL schema and table/view name holding the geometry (e.g., name = c("schema","table"))

rast

Name of the column in name holding the raster object

bands

Index number(s) for the band(s) to retrieve (defaults to 1). The special case (bands = TRUE) returns all bands in the raster.

boundary

sp object or numeric. A Spatial* object, whose bounding box will be used to select the part of the raster to import. Alternatively, four numbers (e.g. c([top], [bottom], [right], [left])) indicating the projection-specific limits with which to clip the raster. boundary = NULL (default) will return the full raster.

clauses

character, optional SQL to append to modify select query from table. Must begin with 'WHERE'.

Author

David Bucklin

Details

Default is to return a raster-class object RasterLayer for one-band, RasterBrick for multiple bands. sp-class rasters (SpatialGrid*s or SpatialPixels*) written using pgWriteRast will attempt to re-import as the same data class.

Examples

if (FALSE) {
pgGetRast(conn, c("schema", "tablename"))
pgGetRast(conn, c("schema", "DEM"), boundary = c(55,
    50, 17, 12))
}