computer science

GvSIG

GvSIG is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand GvSIG rather than just read about it. In short: gvSIG, geographic information system (GIS), is a desktop application designed for capturing, storing, handling, analyzing and deploying any kind of referenced geographic information in order to solve complex management and planning problems. gvSIG is known for having a user-friendly interface, being able to access the most common formats, both vector and raster ones. It features a wide range of tools for working wit…

Key takeaways

GvSIG belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect GvSIG to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of GvSIG from memory before moving on to harder problems.

Reference excerpt

gvSIG, geographic information system (GIS), is a desktop application designed for capturing, storing, handling, analyzing and deploying any kind of referenced geographic information in order to solve complex management and planning problems. gvSIG is known for having a user-friendly interface, being able to access the most common formats, both vector and raster ones. It features a wide range of tools for working with geographic-like information (query tools, layout creation, geoprocessing, networks, etc.).

Integrating in the same view both local (files, databases) and remote data through OGC standards. Including a plugin system which allows to easily extend the application or to develop tailor-made solutions. Being open source software under the GNU General Public License (GPL), which allows its free use, distribution, study and improvement. Being available in several languages: Spanish, English UK, English USA, German, French, Italian, Portuguese, Portuguese-Brazilian, Russian, Chinese, Serbian, Swahili, Turkish, Czech, Polish, Romanian, Greek, Basque, Valencian/Catalan, Galician. Being developed using Java, and being available for Linux, Windows and Mac OS X platforms

Nomenclature gvSIG was initially developed for the Generalitat Valenciana (gv), an institution of the self-governed autonomous community of Valencia. This explains the abbreviation gvSIG for which the last three letters stands for Sistema d'informació geogràfica (SIG), or GIS in English.

Features gvSIG Desktop

Typical tools in a full-fledged desktop GIS client can also be found in gvSIG, among other things:

Access to vector formats: SHP, DXF, GML, DWG, DGN, KML. Access to raster formats: BMP, GIF, TIFF, JPEG, JP2, PNG, VRT, DAT of ENVI, ERDAS (LAN, GIS, IMG), PCI Geomatics (PIX, AUX), ADF of ESRI, ILWIS (MPR, MPL), MAP of PC Raster, ASC, PGM, PPM, RST of IDRISI, RMF, NOS, KAP, HDR, RAW. Access to remote services: OGC (WMS, WFS, WCS, WFS-T, WPS), ArcIMS, Ecwp. Access to databases and tables: PostGIS, ArcSDE, JDBC, CSV. Display:zooms, panning, frames, locator. Query: information, area and distance measurement, hyperlink. Selection: by point, by rectangle, by polygon, by layer, by polyline, by circle, by buffer zone, alphanumeric search, invert selection, delete selection. Searching: by attribute, by coordinates. Geoprocessing: buffer, intersection, clip, dissolve, union, convex hull, difference, merge, spatial join, XY shift, reprojection, Sextante geoprocessing. Graphical editing: add event layers, snapping, grid, flatness, command stack, undo/redo, copy, move, symmetry, rotate, scale, edit vertex, internal polygon, matrix, explode, split, join, autocomplete polygon, insert point, multipoint, line, arc, polyline, polygon, rectangle, square, circle, ellipse. Alphanumeric editing: manage fields, edit registers, field calculator. Catalogue and gazetteer services Vector representation: unique symbol, quantities (dot density, intervals, graduated symbols, proportional symbols), categories (expressions, unique values), multiple attributes, save/load legend, symbology constructor, symbology levels, symbology libraries. Raster representation: brightness, contrast, enhance, transparency by pixel, opacity, colour tables, gradients. Labeling: Static labeling, advanced labeling, individual labeling. Tables: statistics, filter, ascending/descending order, link, join, move selection, export, import fields, coding, normalization. Layout constructor: page layout, cartographic elements (view, legend, north, scale, frames, image, text, graphic), grid, templates. Printing: to PDF, to Postscript, export to several image formats. Network analysis: network topology, stops manager, minimum path, connectivity, minimum spanning tree, origin - destination matrix, emergency / nearest facilities provider, service areas. Raster and remote sensing: statistics, filters, histogram, scale range, enhance, save to raster file, vectorization, Region of Interest (ROI) definition, general components, georeferencing, geolocation, supervised classification, band algebra, image profiles, decision tree, main components, tasseled cap, image fusion, scatter diagram, mosaics. Publishing: MapServer's WCS, WMS and WFS, Geoserver's WFS. 3D and animation: 3D Views, XYZ-projected as well as spherical (planetary), 3D layers, 3D symbology, 3D editing, 3D framing, 2D and 3D animation, stereo viewing (horizontal split). Topology: topological building, topological editing, generalization, reverse line direction, polygons from/to lines, lines from/to points, Delaunay triangulation, Thiessen polygons, build, clean, topological error fixing (in Batch mode). Other: Coordinates Reference Systems manager, import from/export to WMC, scripting, translations manager. Sextante GIS has been ported to a plugin for gvSIG adding analysis functions for raster datasets in addition to gvSIG's built-in vector analysis tools. Within Sextante, GRASS GIS can be used as extension to make its algorithms available to gvSIG users.

gvSIG Mobile gvSIG Mobile aims at broadening gvSIG execution platforms to a range of mobile devices, in order to give an answer to the needs of a growing number of mobile solutions users, who wish to use a GIS on different types of devices. So far, gvSIG Mobile is a Geographic Information System, as well as a Spatial Data Infrastructures client for mobile devices. Such a client is also the first one licensed under open source. gvSIG Mobile is known for:

integrating in the same view both local and remote data through OGC standards. being open source software, under the GNU GPL v2, what allows its free use, distribution, study and improvement. being available in several languages (Spanish, English, German, French, ...) . being developed using Java, and it's available for platforms supporting Java Micro Edition CDC 1.1. So far, it runs on the following platforms: Windows Mobile 5.0, Windows Mobile 6.0 and Nokia Maemo

Features gvSIG Mobile

Typical tools in a mobile GIS client can also be found in gvSIG Mobile:

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Illustrations

Worked examples

Example 1 — a first encounter with GvSIG

Start with the simplest possible case. Write down what GvSIG claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to GvSIG before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about GvSIG ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of GvSIG

In research: GvSIG appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses GvSIG in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: GvSIG is common in secondary-school and first-year university syllabi. It links to neighbouring topics Free GIS software, Free software programmed in Java, Geographic information systems, so understanding it makes those chapters shorter.
In everyday life: Look for GvSIG outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study GvSIG in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what GvSIG means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain GvSIG out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is GvSIG in simple terms?

Why does GvSIG matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study GvSIG?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on GvSIG.