e.g. at the top of a shell script:

```#!/bin/sh
############################################################################
#
# MODULE:       v.in.e00
#
# AUTHOR(S):    Markus Neteler, Otto Dassau
#
# PURPOSE:      Import E00 data into a GRASS vector map
#               Imports single and split E00 files (.e00, .e01, .e02 ...)
#
# COPYRIGHT:    (c) 2004, 2005 GDF Hannover bR, http://www.gdf-hannover.de
#
#               This program is free software under the GNU General Public
#               for details.
#
#############################################################################
#
# REQUIREMENTS:
#      -  avcimport: http://avce00.maptools.org

[script follows]
```

## Shell script coding standards

Please have a look at our Shell script coding standards before submitting here.

• utm_which_zone.sh is a shell script to determine UTM zone from Lat/Lon input. Requires Octave to be installed. A shell-only version is available which only requires awk.

Authors: Hamish Bowman (Octave part), Markus Neteler (shell script wrapper), Daniel Calvelo (sh+awk version)

• Perl scripts for converting data forth and back between Excel files and PostgreSQL: pg2xls.pl reads data from PostgreSQL and produces an excel workbook; xls2sql.pl reads excel files and outputs SQL statements to be fed into an RDBMS. Both scripts need modules from CPAN, especially Spreadsheet::ParseExcel for xls2sql.pl and Spreadsheet::WriteExcel::FromDB and its dependencies for pg2sql.pl. Check the source headers for more info.

Authors: Daniel Calvelo (xls2sql.pl), Markus Neteler (pg2xls.pl)

• azimuth2.c is a small C programm to calculate the azimuth and length of vector lines exported by GRASS-GIS as ASCII files (like this: v.out.ascii input=vector output=ascii format=standard). It is useful for create rose diagrams of lineament maps. Improvements on the original code after suggestions by Örs Téglásy, Hungary.

Author: Carlos Henrique Grohmann

## GRASS 6.x

• v.trees3d is module for making 3D trees from input vector point file.

Author: Jachym Cepicky

• v.lda is a shell script for calculating Ian Johnson's (U. Sidney) Local Density Analysis values to measure clustering of point data at different neighborhood radii. There is an option to create a simple line graph of the results. There have been reports of problems creating the line graph on Cygwin installations of GRASS.

Author: Michael Barton

• v.append is a shell script combining two vector files AND their associated attribute tables. The vector files should be of the same type and, for best results, should have identically formatted attribute tables.

Author: Michael Barton

• v.group generates a new vector map with the same geometry as an existing map. The new map has categories and a table based on grouping by the values in certain columns of the existing map's table. The values in these columns are preserved in the table for the new map. It's like a v.reclass that preserves data.

Author: Cedric Shock

• v.out.ascii.db is a shell script for exporting vector point data coordinates and selected attribute columns to either a file or to the console.

Author: Hamish Bowman

• v.rasterbounds is a shell script for creating polygon-vector file of rasterfile boundaries. The best version of GRASS is 6.1+. If you are using GRASS < 6.1, you have to be in the same mapset as your raster maps are from.

Author: Jachym Cepicky

• v.3Dtin is a shell script for making 3D-vector of the 2D ouput from v.delauny.

Author: Jachym Cepicky

• v.sample.buffer is a shell script that samples rasters in buffers of a specified size around features in a specified vector file. Sampling results are added as attributes to the vector file. This script was designed for sampling vegetation indices and DEM derived attributes for bird point counts. Sampling results can be one or more basic statistics such as mean, range, max, etc.

Author: Trevor Wiens

• v.variogram is a script that create an omnidirectional experimental semi-variogram. This scripts require R-statistics software installed on your machine.

Author: Ivan Marchesini, Pierluigi De Rosa

• v.krige is a script that do a surface interpolation from vector point data by Kriging method.The interpolated value of a cell is determined by using an omnidirectional variogram model fitted starting from model parameter given by user desumed from the experimental semi variogram produced by v.variogram.

Author: Ivan Marchesini, Pierluigi De Rosa

• v.lmeasure and v.revlmeasure are two perl scripts that place equidistant vector points along a given arbitrary vector line starting from the beginning or end of the vector line, respectively. Resulting vector points are labeled with the distance from origin.

Author: Mats Schuh

• v.swathwidth creates a vector map representing the sea bottom coverage of a multibeam (swath) sonar survey.

Author: David Finlayson

• r.gauss is Gaussian and Laplacian of Gaussian filter for GRASS. It is written in C language.

Author: Jachym Cepicky

• r.mlv is Mean of least variance filter for GRASS. It is an edge-preserving (or even edge-enhacing) filter, which should serve for removing additive noise from images. It is written in C language.

Author: Jachym Cepicky

• r.bilateral Bilateral filter is an edge-preserving filter, which combines domain and range filtering. It is written in C language.

Author: Jachym Cepicky

• Zero crossing is a simple Perl script, finds the ,,zero crossings`` from the Laplacian of Gaussian filter (see above). It is really very simple, the edges don't need to be really on that pixel, where they are detected, no interpolation is performed.
```    Usage:
zc.pl -i input -o output |r.mapcalc
```

Author: Jachym Cepicky

• Local maxima is a Perl script for `r.mapcalc`. It detects local maxima of the image.
```    Usage:
local_maxima.pl -i input -o output -s matrix_size|r.mapcalc
```

Author: Jachym Cepicky

• r.out.gmt is a GRASS script for exporting a GRASS raster map into a [GMT] grid file. It also creates a GMT color table from the data and can generate some GMT commands for plotting a postscript file. (code is experimental, but functional)

Authors: Hamish Bowman, Dylan Beaudette

• r.pack and r.unpack are two GRASS scripts for transfering raster maps to another computer as a single file.

Author: Hamish Bowman

• dominant_dir.m and calc_terraflow_dir.m are two Matlab scripts for determining the dominant flow direction from a r.terraflow MFD map and converting into a GRASS aspect map for use with d.rast.arrow, etc.

Author: Hamish Bowman

• r.in.onearth for download and import satellite images direct from the NASA onearth WMS server into GRASS.

Author: Soeren Gebbert

• r.tileset generates a list of tiles and sizes in a source projection that cover the region in the current database with appropriate resolution. The size of individual tiles can be constrained. Only tiles intersecting the current region are returned. These tilings are appropriate for requesting data from another projection to meet the specifications of the current region. For example, it could be used to generate tile requests to a latitude / longitude WMS server like this `r.tileset -w sourceproj="+init=epsg:4326"`.

Author: Cedric Shock

• r.csr integrates several Grass programs to produce colored, shaded-relief rasters in one step. Accepts single or multiple elevation/bathymetry maps as input; optionally will fill data holidays with 3x3 median filter, multiple times, if required; can apply color maps from a) input raster, b) another raster in MAPSET, or c) from a rules file. Output colored, shaded-relief rasters can optionally be exported to tiff format and archived using tar with gzip/bzip2 compression if appropriate flags are given. Shading parameters can be modified, though useful defaults are given.

Author: Eric Patton

• r.fragment fragments a raster into a user-defined set of smaller tiles according to an input number of rows and columns. Optionally, a null value threshold can be set to filter out candidate tiles that would have a large percentage of null cells.

Author: Eric Patton

• r.eucdist creates a raster map estimating the eucledian distance from known cells

Author: David Finlayson

• r.smoothpatch creates a composite of two rasters using a distance-weighted average across the transition to smooth the edges.

Author: David Finlayson ${\displaystyle Insertformulahere}$

• g.laptop.sh is an interactive shell script to extract raster and vector data from current Location into a new one. Data can be copied or extracted in current or original resolution and region extend. This script was written to extract smaller parts of a GRASS location to be able to present them on a laptop without the necessity to transfer huge data. Maps do not have to be in the same mapset.

Author: Otto Dassau

• Readline completion for GRASS commands under the bash shell: grass-complete won't clutter the environment but needs to be installed; grass_rlcompleter.sh needs almost no installation but will pollute the environment.

Author: Alexandre Sorokine (grass-complete), Daniel Calvelo (grass_rlcompleter.sh)

#### IconSymbols

d.out.gpsdrive - moved into GRASS CVS.

• d.stations is a shell script that quickly displays vector points (or sites for GRASS 5.4 and below).

Author: Hamish Bowman

d.hyperlink is an interactive shell script that allows the viewing of hyperlinked images from a vector's attribute table in an external image viewer. Queries can be made via SQL statements or interactive mouse-clicking. The attribute table must be pre-populated with a column containing the image to link the vector to; the user also specifies the image folder in the current MAPSET where the images are located. The script currently supports gimp, Eye of Gnome, gthumb, gpdf, and Inkscape image viewers.

Author: Eric Patton

• d.varea is a shell script that quickly displays vector areas.

Author: Hamish Bowman