Designing and Performing Geographic Analysis Processes with GISCASE Cirano Iochpe, Guillermo N. Hess, Cláudio Ruschel, Alécio P. D. Binotto, Luciana V. da Rocha UFRGS – Instituto de Informática { ciochpe, hess, claudior, abinotto, vargas

Introduction GeoFrame-A Framework GISCASE’S Architecture Implementation Conclusions and Future Work Main Topics

Introduction Each GIS tool supports its own logical model for both data and process design. A need: Models and tools that help the definition / design of geographic data and analysis processes. Tools used in GDB design could be candidates (ex: MADS, GeoOOA, GeoFrame), if they also supported process definition. GeoFrame-A: an extension to the GeoFrame Framework that aims to support the design of geographic analysis processes. Our proposal: GISCASE: software tool that implements GeoFrame-A concepts. It generates programs that can perform geographic analysis processes.

The GeoFrame Framework: GeoFrame is an object oriented conceptual framework on the basis of the Unified Modeling Language (UML) (Lisboa, 2000). It supports geographic database design by providing a set of classes that can be instatiated as well as specialized, and extended. GeoFrame-A: Extension that supports the design of geographic analysis processes (Ruschel, 2003). The GeoFrame-A Framework

GeoFrame-A uses UML 2 diagrams to specify processes: -Class Diagram: external specification Each geographic process type is represented as an Activity Class. The GeoFrame-A Framework

-Activity Diagram: internal specification Data represented as object nodes; Operations modeled as activity nodes; Both data and control flow possible. A set of basic geoprocessing operations {DS (Dissolve) ; OV (Overlay) ; SS (Spatial Selection) ; BF (Buffer)...} The GeoFrame-A Framework

The GISCASE Tool GISCASE is a free software developed at UFRGS that generates source code in a programming language which, when compiled and executed, performs geographic analysis processes. The specification uses UML activity diagrams including GeoFrame-A concepts. Spatial classes are represented through spatial tables in a GDB. Operations must be implemented on a GIS software API. First implementation relies upon TerraLib.

GISCASE’s Architecture

GisCase Main Window: Manages GISCASE’s workflow. Elements: navigation panel, text editor, message window GISCASE’s Architecture

Graphical Editor Activity diagrams: CASE tool Poseidon UML (Community Edition) GISCASE’s Architecture

GPtoXML Parser Reads the XMI file and performs a semantic analysis. Result: a clean XML file, from which code generation is possible. GISCASE’s Architecture

Elements from the XMI file are coded into a new XML file, based on a XML-Schema (the XML encode for GeoFrame-A). GPtoXML Parser GisCase_DS_1 polygon GisCase_DS_1 XMI File XML-Schema Generated XML File GISCASE’s Architecture

Object nodes serve as either input or output for Action nodes. Each action node can have one or more input nodes but only one output. Actions are verified within GP Rules database: Number of inputs for each action; Data types of the inputs and outputs. GPtoXML Parser GISCASE’s Architecture

XMLtoGIS Generator Generates source code from the XML specification. GISCASE’s Architecture

For each GIS software an API is needed in order to map GeoFrame-A operations onto the logical model of the GIS software. XMLtoGIS Generator bool GcBuffer(string inLayerName, TeGeomRep inRepName, string outLayerName, double dist, TeAdo* db) {TeLayer* inLayer = new TeLayer(inLayerName); db->loadLayer(inLayer); TeProjection* proj = inLayer->projection ();... TePolygonSet bufferPol; TeLayer* outLayer = new TeLayer(outLayerName, db, inLayer->box(), inLayer->projection()); int layerId = outLayer->id(); db->Buffer(tableRep, inRepName,objsIn, bufferPol, dist); outLayer->addPolygons(bufferPol); } This module generates the source code that accesses the GIS operations through its API, passing respective parameters when needed. The source code generated must be compiled and linked with the required GIS libraries, or interpreted within the GIS software environment. Mapping the buffer operation to TerraLib GISCASE’s Architecture

Implementation ComponentRequisitesAdopted Graphical Editor must implement an actitivy diagram and generate a XML- like output Gentleware's Poseidon (Community Edition) GIS API must manage a GDB and functions of geographic analysisTerraLib from INPE Interface platform with interface components Eclipse Platform As a free software project sponsored by CNPq, all the external components adopted are free software. Interface and parsers built in Java: free software, platform independent, easy to parse XML files GISCASE’s exclusive Library to access TerraLib API developed in C++

Implementation The XMLtoGIS module generates a main procedure and appends the source code for the operations used in the process from the library GcGeoOperations for TerraLib. int main(){ string dbname = "C:\GeoDB\Geoinfo.mdb"; TeAdo* db = new TeAdo(); db->connect("localhost","","",dbname,0)) cout errorMessage() << endl; TeAdoPortal* dbPortal = new TeAdoPortal(db); TeDatabasePortal* portal = dbPortal; TeInitQuerierStrategies(); val = GcDissolve("Municipality","GisCase_DS_1","IDADMREGION",db, portal); if (!val) cout << "Erro na função GcDissolve!" << endl; val = GcOverlay("GisCase_DS_1","River_Basin","Region_by_Basin","AND",db, portal); if (!val) cout << "Erro na função GcOverlay!" << endl; portal->freeResult(); db->close(); return 0; }

Implementation GcGeoOperations Library for TerraLib Source code that maps the main procedure to TerraLib library and TerraView functions. Operations implemented in the first version: GcSelection: selects objects by attributes GcRegionSelection: selects objects inside a polygon GcSpatialSelection: selects objects through a spatial predicate GcBuffer: creates a polygon with a specified distance GcOverlay: does the overlay of two sets of spatial objects GcDissolve: generalizes the input objects through an attribute GcCentroid: finds the centroid of a polygon GcAlgebra: updates attributes in one layer (SQL Update) GcDistance: mesures the distance of two geometries

Prepare a GDB, compatible to the GIS API, with the input data In the GISCASE tool: - Design the process in the graphical editor - Verify semantics and generate source code Compile and execute (for TerraLib, with Visual Studio) Verify the results in a map viewer (ex: TerraView) Workflow to perform a geographic analysis process with GISCASE:

Contributions: a XML schema able to define a geographic process complements a set of applications developed with TerraLib a modular and extendable architecture to design geographic process a learning tool to programmers Future work: to implement other geographic analysis operations still using TerraLib code generation for other GIS platforms allow the use of a script language as an alternative to the graphical editor