Difference between revisions of "TerraHS"

Revision as of 11:55, 25 November 2009

What is it ?

is a software component that enables the development of geographical applications in a functional language, using the data handling capabilities of TerraLib. TerraLib is a C++ library that supports different spatial database management systems, and that includes a large number of spatial algorithms. As a result, we get a combination of the good features of both programming paradigms.

How to use Haskell for GIS

Features

The major features are:

Input and output formats: Layers or themes from TerraLib databases (just MySQL), Esri Shape File (*.shp), TIFF file.
Data types: Raster or image (just 8 bits), Vectors (Point, Line, Polygon and Cell), Temporal (DateTime, Interval)
Topological operators: intersects, within, touches, crosses ...
Geometric operations: intersection, union, difference, rotation.
Metrical operations: perimeter, area, distance, centroid, shapeindex, compacity, fractal

Demos

The following figure is one example of a vector data can be exported to a TerraLib database, and then it can be visualized with TerraView.

The pattern for a main program in TerraHS has the folowing structure:

module Main(main) where

import TerraHS

host = "localhost";
dbname =  "demo_terrahs";
user = "root";
password = "root";

main:: IO()
main = do
	-- loading a vector data from a shape file
	gos <- loadVectorFile "MG_MUN96.shp"
	-- open a connection
	db <- open (TeMySQL host user password dbname)
	-- saving in a database layer
	store db "layer_name" gos
	print "saved"

Two different outcomes from a image data and theirs respective operations (a)input image, (b) inverted image and (c) reverse image.

The following examples use this data:

Its possible to run in the ghci:

 #ghci SpatialOper.hs

printing some test values, e.g.:

 Main> main
 Loading package syb ... linking ... done.
 Loading package base-3.0.3.0 ... linking ... done.
 Loading package terrahs-0.8 ... linking ... done.
 TePoint (12.5,10.0)
 TeLine2D [(1.0,1.0),(1.0,2.0),(1.0,7.0)]
 TePolygon [TeLine2D [(1.0,1.0),(1.0,2.0),(3.0,2.0),(3.0,1.0),(1.0,1.0)]]
 False
 True
 False
 2.0

or compile and run:

#ghc SpatialOper.hs -package terrahs-0.8 -o main
#main

More details about the api in source documentation - online (HTML)

Download and Installation

TerraHS is available in cabal package from Hackage. See How to install a Cabal package in Linux or Windows.

Installation notes for Linux

Software dependencies in debian package

The installation procedure:

 #sudo dpkg -i package.deb

The uninstallation procedure:

 #sudo dpkg -r package

Software dependencies in source file

The installation procedure:

#tar xvzf package.tar.gz
#cd package
#./configure
#make
#sudo make install

The uninstallation procedure:

 #cd package
 #sudo make uninstall

Installation notes for Windows

Coming soon

Software dependencies

TerraHS is a Haskell GIS application built using the TerraLib GIS library. In below, is available a debian packages for TerraLib. TerraHS-0.8 uses the TerraLib-3.3.0 version.

TerraLib-3.3.0 for (Ubuntu 9.04 (x86))

Optional, but is recommended to install the TerraView application.TerraView is a GIS application based on TerraLib, a GIS library to handle vector and raster data in geographical DBMS such as Access, PostgreSQL, MySQL and Oracle Spatial.

TerraView-3.3.0 for (Ubuntu 9.04 (x86))

The TerraLib and TerraView source files can be downloaded from official sites:

TerraLib
TerraView.

We have developed some specific libraries to support some functionalities for TerraHS. The libraries can be installed from an unique package (TerraLib4c+Translib)

TerraHSdependecies for Ubuntu 9.04 (x86)

Or can be download in separated way:

Translib, a library for translation among different geographic format files (no database connection), based in the TerraLib library. This library is required for TerraHS to deal whith shape files (*.shp).

Ubuntu 9.04 (x86)

Source, generic Linux

Terralib4c, a library that maps c++ Terralib functions and classes to C functions. Required by Haskell to do binding with TerraLib api.