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Feições

QGIS offers many common GIS functionalities provided by core features and plugins. A short summary of six general categories of features and plugins is presented below, followed by first insights into the integrated Python console.

Visualização de dados

You can view and overlay vector and raster data in different formats and projections without conversion to an internal or common format. Supported formats include:

  • Spatially-enabled tables and views using PostGIS, SpatiaLite and MS SQL Spatial, Oracle Spatial, vector formats supported by the installed OGR library, including ESRI shapefiles, MapInfo, SDTS, GML and many more. See section Trabalhando com Dados Vetoriais.

  • Formatos de imagens e Raster suportados pela biblioteca GDAL instalada (Geospatial Data Abstraction Library), como GeoTIFF, ERDAS IMG, ArcInfo ASCII GRID, JPEG, PNG e muitos mais. Consulte a seção Trabalhando com Dados Raster.

  • Dados vetoriais e raster GRASS para base de dados GRASS (location.mapset). Ver seção Integração com SIG GRASS.

  • Servidores de dados espaciais online como Serviços Web OGC, incluem WMS, WMTS, WCS, WFS, e WFS-T. Ver seção Trabalhando com dados OGC.

Exploração de dados e compositores de mapas

Você pode compor mapas e interativamente explorar dados espaciais com uma interface gráfica amigável. As muitas ferramentas úteis disponíveis na GUI incluem:

  • QGIS browser

  • Reprojeção On-the-fly

  • Gerenciador BD

  • Map composer

  • Painel de Vista Global

  • Marcadores espaciais

  • Ferramentas de anotação

  • Identificar/selecionar feições

  • Editar/ver/procurar atributos

  • Data-defined feature labelling

  • Ferramentas de simbologia raster e vetorial dado definido

  • Compositor de Atlas com camada grade

  • North arrow scale bar and copyright label for maps

  • Suporte para salvamento e restauração de projetos

Criar, editar, gerir e exportar dados

You can create, edit, manage and export vector and raster layers in several formats. QGIS offers the following:

  • Ferramentas de digitalização para formatos suportados OGR e camadas vetoriais GRASS

  • Ability to create and edit shapefiles and GRASS vector layers

  • Complemento Georreferenciador para geocodificar imagens

  • GPS tools to import and export GPX format, and convert other GPS formats to GPX or down/upload directly to a GPS unit (On Linux, usb: has been added to list of GPS devices.)

  • Suporte para visualização e edição de dados OpenStreetMap

  • Ability to create spatial database tables from shapefiles with DB Manager plugin

  • Tratamento melhorado de tabelas de bases de dados espaciais

  • Ferramentas para gerenciamento de tabelas de atributos vetoriais

  • Opção para salvar as imagens como imagens georreferenciadas

  • ferramenta de exportação DXF com recursos aprimorados para exportar estilos e complementos para executar funções CAD-like

Analyze data

You can perform spatial data analysis on spatial databases and other OGR- supported formats. QGIS currently offers vector analysis, sampling, geoprocessing, geometry and database management tools. You can also use the integrated GRASS tools, which include the complete GRASS functionality of more than 400 modules. (See section Integração com SIG GRASS.) Or, you can work with the Processing Plugin, which provides a powerful geospatial analysis framework to call native and third-party algorithms from QGIS, such as GDAL, SAGA, GRASS and more. (See section Introdução.)

Publicação de mapas na internet

QGIS can be used as a WMS, WMTS, WMS-C or WFS and WFS-T client, and as a WMS, WCS or WFS server. (See section Trabalhando com dados OGC.) Additionally, you can publish your data on the Internet using a webserver with UMN MapServer or GeoServer installed.

Extend QGIS functionality through plugins

QGIS can be adapted to your special needs with the extensible plugin architecture and libraries that can be used to create plugins. You can even create new applications with C++ or Python!

Complementos Core

Complementos incluídos no programa

  1. Coordinate Capture (Capture mouse coordinates in different CRSs)
  2. DB Manager (Exchange, edit and view layers and tables from/to databases; execute SQL queries)
  3. Dxf2Shp Converter (Convert DXF files to shapefiles)
  4. eVIS (Visualize events)
  5. GDALTools (Integrate GDAL Tools into QGIS)
  6. Georeferencer GDAL (Add projection information to rasters using GDAL)
  7. GPS Tools (Load and import GPS data)
  8. GRASS (Integrate GRASS GIS)
  9. Heatmap (Generate raster heatmaps from point data)
  10. Interpolation Plugin (Interpolate based on vertices of a vector layer)
  11. Metasearch Catalogue Client
  12. Offline Editing (Allow offline editing and synchronizing with databases)
  13. Oracle Spatial GeoRaster
  14. Processing (formerly SEXTANTE)
  15. Raster Terrain Analysis (Analyze raster-based terrain)
  16. Road Graph Plugin (Analyze a shortest-path network)
  17. Spatial Query Plugin
  18. Topology Checker (Find topological errors in vector layers)
  19. Zonal Statistics Plugin (Calculate count, sum, and mean of a raster for each polygon of a vector layer)

Complementos Externos Python

QGIS offers a growing number of external Python plugins that are provided by the community. These plugins reside in the official Plugins Repository and can be easily installed using the Python Plugin Installer. See Section Diálogo de Complementos.

Console Python

For scripting, it is possible to take advantage of an integrated Python console, which can be opened from menu: Plugins ‣ Python Console. The console opens as a non-modal utility window. For interaction with the QGIS environment, there is the qgis.utils.iface variable, which is an instance of QgsInterface. This interface allows access to the map canvas, menus, toolbars and other parts of the QGIS application. You can create a script, then drag and drop it into the QGIS window and it will be executed automatically.

For further information about working with the Python console and programming QGIS plugins and applications, please refer to Passo-a-passo para desenvolvedor PyQGIS.

Problemas conhecidos

Limitação no número de arquivos abertos

Se você está abrindo um grande projeto QGIS e você tem certeza de que todas as camadas são válidas, mas algumas camadas são sinalizadas como ruim, você provavelmente irá se confrontar com esta questão. O Linux (e outros sistemas operacionais, da mesma forma) tem um limite de arquivos abertos por processo. Limites de recursos por processo e hereditária. O comando ulimit, que é um shell integrado, muda os limites apenas para o processo de shell atual; o novo limite será herdado por quaisquer processos filhos.

You can see all current ulimit info by typing:

$ ulimit -aS

You can see the current allowed number of opened files per process with the following command on a console:

$ ulimit -Sn

To change the limits for an existing session, you may be able to use something like:

$ ulimit -Sn #number_of_allowed_open_files
$ ulimit -Sn
$ qgis

Para fixar isso sempre

Na maioria dos sistemas Linux, limites de recursos são definidos no login pelo módulo pam_limits de acordo com as definições contidas no /etc/security/limits.conf ou /etc/security/limits.d/*.conf. Você será capaz de editar os arquivos, se você tem privilégios de root (também via sudo), mas você vai precisar fazer login novamente para que as alterações tenham efeito.

Mais informações:

http://www.cyberciti.biz/faq/linux-increase-the-maximum-number-of-open-files/ http://linuxaria.com/article/open-files-in-linux?lang=en