gdalraster is an R interface to the Raster API of the Geospatial Data Abstraction Library (GDAL). Calling signatures resemble those of the native C, C++ and Python APIs provided by the GDAL project.

Bindings to GDAL are implemented in the exposed C++ class GDALRaster along with several stand-alone functions, supporting:

• manual creation of uninitialized raster datasets
• creation from existing raster as template
• read/set raster dataset parameters
• low-level I/O
• read/set color tables and raster attribute tables
• copy files/move/rename/delete datasets
• virtual raster (VRT) for virtual subsetting, resampling and kernel filtering
• gdalwarp wrapper for reprojection
• coordinate transformation
• spatial reference convenience functions
• several GDAL algorithms

Additional functionality includes:

• class RunningStats calculates mean and variance in one pass, and tracks the min, max, sum, and count (i.e., summary statistics on a data stream). The input data values are not stored in memory, so this class can be used to compute statistics for very large data streams.
• class CmbTable identifies and counts unique combinations of integer values using a hash table.
• combine() overlays multiple rasters so that a unique ID is assigned to each unique combination of input values. Pixel counts for each unique combination are obtained, and combination IDs are optionally written to an output raster.
• calc() evaluates an R expression for each pixel in a raster layer or stack of layers. Individual pixel coordinates are available as variables in the R expression, as either x/y in the raster projected coordinate system or inverse projected longitude/latitude.
• plot_raster() displays raster data using base R graphics.

gdalraster may be suitable for applications that primarily need low-level raster I/O or prefer a direct GDAL API. The additional functionality is somewhat aimed at thematic data analysis but may have other utility.

# Install the released version from CRAN
install.packages("gdalraster")

# Or the development version from GitHub:
remotes::install_github("USDAForestService/gdalraster")

• Reference Manual
• Raster API Tutorial
• Raster Attribute Tables
• Raster Display
• GDAL Block Caching