Geographic Resources Analysis Support System, commonly referred to as GRASS, is a Geographic Information System (GIS) used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization. GRASS is currently used in academic and commercial settings around the world, as well as by many governmental agencies and environmental consulting companies.
This reference manual details the use of modules distributed with Geographic Resources Analysis Support System (GRASS), an open source (GNU GPL'ed), image processing and geographic information system (GIS).
raster commands:
| r.average | Finds the average of values in a cover map within areas assigned the same category value in a user-specified base map. |
| r.basins.fill | Generates a raster map layer showing watershed subbasins. |
| r.bilinear | Bilinear interpolation utility for raster map layers. |
| r.bitpattern | Compares bit patterns with a raster map. |
| r.blend | Blends color components of two raster maps by a given ratio. |
| r.buffer | Creates a raster map layer showing buffer zones surrounding cells that contain non-NULL category values. |
| r.carve | Takes vector stream data, transforms it to raster and subtracts depth from the output DEM. |
| r.category | Manages category values and labels associated with user-specified raster map layers. |
| r.circle | Creates a raster map containing concentric rings around a given point. |
| r.clump | Recategorizes data in a raster map layer by grouping cells that form physically discrete areas into unique categories. |
| r.coin | Tabulates the mutual occurrence (coincidence) of categories for two raster map layers. |
| r.colors | Creates/modifies the color table associated with a raster map layer. |
| r.composite | Combines red, green and blue map layers into a single composite map layer. |
| r.compress | Compresses and decompresses raster maps. |
| r.contour | Produces a vector map layer of specified contours from a raster map layer. |
| r.cost | Outputs a raster map layer showing the cumulative cost of moving between different geographic locations on an input raster map layer whose cell category values represent cost. |
| r.covar | Outputs a covariance/correlation matrix for user-specified raster map layer(s). |
| r.cross | Creates a cross product of the category values from multiple raster map layers. |
| r.describe | Prints terse list of category values found in a raster map layer. |
| r.digit | Interactive tool used to draw and save vector features on a graphics monitor using a pointing device (mouse) and save to a raster map. |
| r.distance | Locates the closest points between objects in two raster maps. |
| r.drain | Traces a flow through an elevation model on a raster map layer. |
| r.fill.dir | Filters and generates a depressionless elevation map and a flow direction map from a given elevation layer. |
| r.fillnulls | Fills no-data areas in raster maps using v.surf.rst splines interpolation |
| r.flow | Construction of slope curves (flowlines), flowpath lengths, and flowline densities (upslope areas) from a raster digital elevation model (DEM) |
| r.grow | Generates a raster map layer with contiguous areas grown by one cell. |
| r.gwflow | Numerical calculation program for transient, confined and unconfined groundwater flow in two dimensions. |
| r.his | Generates red, green and blue raster map layers combining hue, intensity and saturation (HIS) values from user-specified input raster map layers. |
| r.in.arc | Converts an ESRI ARC/INFO ascii raster file (GRID) into a (binary) raster map layer. |
| r.in.ascii | Converts ASCII raster file to binary raster map layer. |
| r.in.aster | Georeference, rectify and import Terra-ASTER imagery and relative DEM's using gdalwarp. |
| r.in.bin | Import a binary raster file into a GRASS raster map layer. |
| r.in.gdal | Import GDAL supported raster file into a binary raster map layer. |
| r.in.gridatb | Imports GRIDATB.FOR map file (TOPMODEL) into GRASS raster map |
| r.in.mat | Imports a binary MAT-File(v4) to a GRASS raster. |
| r.in.poly | Creates raster maps from ASCII polygon/line/point data files. |
| r.in.srtm | Import SRTM HGT files into GRASS |
| r.in.wms | Downloads and imports data from WMS servers. |
| r.in.xyz | Create a raster map from an assemblage of many coordinates using univariate statistics. |
| r.info | Output basic information about a raster map layer. |
| r.kappa | Calculate error matrix and kappa parameter for accuracy assessment of classification result. |
| r.lake | Fills lake from seed at given level |
| r.le.patch | Calculates attribute, patch size, core (interior) size, shape, fractal dimension, and perimeter measures for sets of patches in a landscape. |
| r.le.pixel | Contains a set of measures for attributes, diversity, texture, juxtaposition, and edge. |
| r.le.setup | Interactive tool used to setup the sampling and analysis framework that will be used by the other r.le programs. |
| r.le.trace | Displays the boundary of each r.le patch and shows how the boundary is traced, displays the attribute, size, perimeter and shape indices for each patch and saves the data in an output file. |
| r.li.cwed | Calculates contrast weighted edge density index on a raster map |
| r.li.daemon | |
| r.li.dominance | Calculates dominance's diversity index on a raster map |
| r.li.edgedensity | Calculates edge density index on a raster map, using a 4 neighbour algorithm |
| r.li | package overview |
| r.li.mpa | Calculates mean pixel attribute index on a raster map |
| r.li.mps | Calculates mean patch size index on a raster map, using a 4 neighbour algorithm |
| r.li.padcv | Calculates coefficient of variation of patch area on a raster map |
| r.li.padrange | Calculates range of patch area size on a raster map |
| r.li.padsd | Calculates standard deviation of patch area a raster map |
| r.li.patchdensity | Calculates patch density index on a raster map, using a 4 neighbour algorithm |
| r.li.patchnum | Calculates patch number index on a raster map, using a 4 neighbour algorithm. |
| r.li.richness | Calculates dominance's diversity index on a raster map |
| r.li.setup | Configuration editor for r.li.'index' |
| r.li.shannon | Calculates Shannon's diversity index on a raster map |
| r.li.shape | Calculates shape index on a raster map |
| r.li.simpson | Calculates Simpson's diversity index on a raster map |
| r.los | Line-of-sight raster analysis program. |
| r.mapcalc | |
| r.mapcalculator | Calculate new raster map from a r.mapcalc expression. |
| r.mask | Create a MASK for limiting raster operation |
| r.median | Finds the median of values in a cover map within areas assigned the same category value in a user-specified base map. |
| r.mfilter.fp | Raster map matrix filter. |
| r.mfilter | Raster map matrix filter. |
| r.mode | Finds the mode of values in a cover map within areas assigned the same category value in a user-specified base map. |
| r.neighbors | Makes each cell category value a function of the category values assigned to the cells around it, and stores new cell values in an output raster map layer. |
| r.null | Creates explicitly the NULL-value bitmap file. |
| r.out.arc | Converts a raster map layer into an ESRI ARCGRID file. |
| r.out.ascii | Converts a raster map layer into an ASCII text file. |
| r.out.bin | Exports a GRASS raster to a binary array. |
| r.out.gdal | Exports GRASS raster map into GDAL supported formats. |
| r.out.gdal.sh | Exports GRASS raster into GDAL supported formats. |
| r.out.gridatb | Exports GRASS raster map to GRIDATB.FOR map file (TOPMODEL) |
| r.out.mat | Exports a GRASS raster to a binary MAT-File. |
| r.out.mpeg | Raster File Series to MPEG Conversion Program. |
| r.out.png | Export GRASS raster as non-georeferenced PNG image format. |
| r.out.pov | Converts a raster map layer into a height-field file for POVRAY. |
| r.out.ppm | Converts a GRASS raster map to a PPM image file at the pixel resolution of the currently defined region. |
| r.out.ppm3 | Converts 3 GRASS raster layers (R,G,B) to a PPM image file at the pixel resolution of the CURRENTLY DEFINED REGION. |
| r.out.tiff | Exports a GRASS raster map to a 8/24bit TIFF image file at the pixel resolution of the currently defined region. |
| r.out.vrml | Export a raster map to the Virtual Reality Modeling Language (VRML) |
| r.out.vtk | Converts raster maps into the VTK-Ascii format |
| r.out.xyz | Export a raster map to a text file as x,y,z values based on cell centers. |
| r.param.scale | Extracts terrain parameters from a DEM. |
| r.patch | Creates a composite raster map layer by using known category values from one (or more) map layer(s) to fill in areas of "no data" in another map layer. |
| r.plane | Creates raster plane map given dip (inclination), aspect (azimuth) and one point. |
| r.profile | Outputs the raster map layer values lying on user-defined line(s). |
| r.proj | Re-projects a raster map from one location to the current location. |
| r.quant | Produces the quantization file for a floating-point map. |
| r.quantile | Compute quantiles using two passes. |
| r.random.cells | Generates random cell values with spatial dependence. |
| r.random | Creates a raster map layer and vector point map containing randomly located sites. |
| r.random.surface | Generates random surface(s) with spatial dependence. |
| r.reclass.area | Reclasses a raster map greater or less than user specified area size (in hectares) |
| r.reclass | Creates a new map layer whose category values are based upon a reclassification of the categories in an existing raster map layer. |
| r.recode | Recodes categorical raster maps. |
| r.region | Sets the boundary definitions for a raster map. |
| r.regression.line | Calculates linear regression from two raster maps: y = a + b*x |
| r.report | Reports statistics for raster map layers. |
| r.resamp.interp | Resamples raster map layers to a finer grid using interpolation. |
| r.resamp.rst | Reinterpolates and optionally computes topographic analysis from input raster map to a new raster map (possibly with different resolution) using regularized spline with tension and smoothing. |
| r.resamp.stats | Resamples raster map layers to a coarser grid using aggregation. |
| r.resample | GRASS raster map layer data resampling capability. |
| r.rescale.eq | Rescales histogram equalized the range of category values in a raster map layer. |
| r.rescale | Rescales the range of category values in a raster map layer. |
| r.ros | Generates three, or four raster map layers showing 1) the base (perpendicular) rate of spread (ROS), 2) the maximum (forward) ROS, 3) the direction of the maximum ROS, and optionally 4) the maximum potential spotting distance. |
| r.series | Makes each output cell value a function of the values assigned to the corresponding cells in the input raster map layers. |
| r.shaded.relief | Creates shaded relief map from an elevation map (DEM). |
| r.sim.sediment | Sediment transport and erosion/deposition simulation using path sampling method (SIMWE) |
| r.sim.water | Overland flow hydrologic simulation using path sampling method (SIMWE) |
| r.slope.aspect | Generates raster map layers of slope, aspect, curvatures and partial derivatives from a raster map layer of true elevation values. Aspect is calculated counterclockwise from east. |
| r.spread | Simulates elliptically anisotropic spread on a graphics window and generates a raster map of the cumulative time of spread, given raster maps containing the rates of spread (ROS), the ROS directions and the spread origins. |
| r.spreadpath | Recursively traces the least cost path backwards to cells from which the cumulative cost was determined. |
| r.statistics | Calculates category or object oriented statistics. |
| r.stats | Generates area statistics for raster map layers. |
| r.sum | Sums up the raster cell values. |
| r.sun | Solar irradiance and irradiation model. |
| r.sunmask | Calculates cast shadow areas from sun position and DEM. Either A: exact sun position is specified, or B: date/time to calculate the sun position by r.sunmask itself. |
| r.support | Allows creation and/or modification of raster map layer support files. |
| r.support.stats | Update raster map statistics |
| r.surf.area | Surface area estimation for rasters. |
| r.surf.contour | Surface generation program from rasterized contours. |
| r.surf.fractal | Creates a fractal surface of a given fractal dimension. |
| r.surf.gauss | GRASS module to produce a raster map layer of gaussian deviates whose mean and standard deviation can be expressed by the user. It uses a gaussian random number generator. |
| r.surf.idw | Surface interpolation utility for raster map layers. |
| r.surf.idw2 | Surface generation program. |
| r.surf.random | Produces a raster map layer of uniform random deviates whose range can be expressed by the user. |
| r.terraflow | Flow computation for massive grids (Float version). |
| r.texture | Generate images with textural features from a raster map. |
| r.thin | Thins non-zero cells that denote linear features in a raster map layer. |
| r.tileset | Produces tilings of the source projection for use in the destination region and projection. |
| r.timestamp | Print/add/remove a timestamp for a raster map. |
| r.to.rast3 | Converts 2D raster map slices to one 3D raster volume map. |
| r.to.rast3elev | Creates a 3D volume map based on 2D elevation and value raster maps. |
| r.to.vect | Converts a raster map into a vector map layer. |
| r.topidx | Creates topographic index [ln(a/tan(beta))] map from elevation map. |
| r.topmodel | Simulates TOPMODEL which is a physically based hydrologic model. |
| r.transect | Outputs raster map layer values lying along user defined transect line(s). |
| r.univar | Calculates univariate statistics from the non-null cells of a raster map. |
| r.univar.sh | calculates univariate statistics from a GRASS raster map |
| r.volume | Calculates the volume of data "clumps", and (optionally) produces a GRASS vector points map containing the calculated centroids of these clumps. |
| r.walk | Outputs a raster map layer showing the anisotropic cumulative cost of moving between different geographic locations on an input elevation raster map layer whose cell category values represent elevation combined with an input raster map layer whose cell values represent friction cost. |
| r.water.outlet | Watershed basin creation program. |
| r.watershed | Watershed basin analysis program. |
| r.what.color | Queries colors for a raster map layer. |
| r.what | Queries raster map layers on their category values and category labels. |
Help Index | Full Index
© 2003-2008 GRASS Development Team
