If the friends of gvSIG They keep their promise, next Monday July 27 we will have version 1.9 stable. So far the testing has been great, according to the volume perceived in the Distribution lists. While Monday arrives, by the time I hope to have the satisfaction of congratulating the word compliance, at the expense of the sure sleeplessness that developers must bring, let's take a look at Quantum GIS like this from a bird's eye view.
QGIS was developed in C ++ using the Qt toolkit, it runs on Windows, Mac and Linux. The project arose in May 2002, with support for 26 languages and its license is GPL.
Quantum GIS Appearance
The iconography and interface design is the most redeemable, it does not affect usability, but it does affect corporate taste (sells) when offering it. Appearance that Previously criticized of gvSIG, because at some point its appearance and disparity of creativity caused a manager to tell me "It looks like a veteran program, some icons seem to have been made with 8 bitstream Paintbrush".
But in this superficiality, QGIS walks very well, even with a simple click you can choose between 3 different themes of iconography very well conceptualized, just pass the mouse by the topic shows how the interface would look.
Quantum GIS interesting features
QGIS requires Grass for many functionalities that that tool has well established, very good for not duplicating efforts. When starting QGIS and not finding it installed, it raises an alert; in this case I am doing a review without including Grass. When I wanted to load a Grass dataset, the application was closed because it was not installed, so I do not recommend using it without installing both tools.
Shortcuts, A lot of commands have a letter assigned, such that the function can be loaded just by pressing this letter. This is very practical, I remember that in AutoCAD it was one of the best tricks when almost every command was done via keyboard.
The overview, on the left panel is a map showing the deployment area, with synchronization in both tracks. Very useful, you can choose which layers you want to see in the overview, and it can also be dropped as a floating window at a different size.
The side frame, just great, you can drag the plugins as labels to the foreground, they can be made floating, and with a simple right button activate or deactivate. Also the width management is simple to drag not only in the left panel but also in the lower one.
The bottom panel, when displaying the attribute table, it appears in the area, but it can also be floating. Very functional, with zoom options to the selected rows and change of column width with a simple drag of the mouse. Also in the lower frame it has the search and select functions, similar to how Manifold GIS does, apart from the simple status bar.
The conformation of this interface design makes it more usable, floating frames is the best, reminds me much Microstation, because for that matter, the attributes window can be displayed without affecting another operation.
Analysis of data, Has the basic aspects of geoprocessing and research that someone could require, at first glance there are some very interesting functions that I prefer to see another time, since the Ftools plugins include terrain modeling, hydrological, among others.
Extra PluginsLike any gpl application, its gain is in the plugins that the community is making little by little (although with the advantage of not being in Java), by default it brings the basics and they seem few but they are not as simple as they seem: they can be loaded WFS layers, export to MapServer, capture a coordinate, add aids to the view such as north, scale and copyright, text delimited by commas, has a dxf to shp converter, plugin to georeference images, gps console, python console, coordinate mesh , etc. But the best thing is the option to load the Grass plugins that are a separate topic. Similar to what happens with gvSIG and Sextante although the maturity of Grass is respectable, one of the oldest GIS tools.
It is interesting the OGR converter, which can convert layers between different formats such as shp, dgn, gpx, gml, csv, kml, mapinfo, as well as spatial BD via ODBC, MySQL, PostgreSQL, among others.
Of the best: dxf to shp and kml to dxf, basic but not done by other payment programs.
Basic functionsLike other tools, you can create spatial bookmarks, groups of layers, the layers have minimum and maximum zoom control, ease of adding coordinate systems and projection; in case of shp layers, if they have prj, Qgis rescues this information. A lot of processes include a progress bar, which we think is very good.
It is very interesting how the attributes of the objects are configured, because in the same panel there are tabs for general properties, symbology, metadata, labels, actions and tabular attributes; everything can be saved as a .qml style and loaded to apply to other layers. Also this table is floating and its width and height can be adjusted to taste. Even this panel and others can be opened as a separate application.
It also calls attention to features that seem simple but that have a great utility, such as the measurement of continuous distances, reflected in a tabular panel, which includes the distance of each segment.
Access and edit data
You can load vector data shp, gml, Mapinfo and ddf, although data from other formats can be converted via the OGR converter. Additionally vector layers via WFS and PostGIS. Redeemable, allows you to specify the character encoding when loading the layer.
As for raster layers, it supports an awful lot, apart from WMS. Additionally includes reading OGC WFS, WCS, CAT, SFS, and GML standards.
To create new vector layers they can be done through OGR shape files or Grass. The projects are saved as XML with a qgs extension, where the gvSIG-style layering is saved.
As for data editing, specifications such as coordinate system, units, decimal precision, enabling topological editing, permission or limitation of overlapping polygons in the same layer and snap conditions (type and tolerance) for each layer available in the project. The latter is interesting, although I was disappointed that it only has a segment and vertex option. I insist, Grass must be a justification for this.
I tried editing a layer, inserting a vertex, but I found it quite slow, other than it was necessary to go to add the options of snapping (Sorry for my clumsiness, it's the first time I play this toy). I'll see it later when I load the Grass editing tools. Nor does there seem to be a track if several are editing a layer simultaneously, whoever saves first wins. ugh!
For quick output purposes, there is an option to save the view as an image, and a plugin for quick printing, but unlike gvSIG, it does not have an ArcView-style layout control; but a print composer that seems a bit taken from the hair, although it allows to load dataframes, labels, boxes and symbols, and several compositions can be created for a project, I did not find how to save them as templates; the manual says it is possible. I guess there are better things in Grass plugins for these purposes.
Quantum gis vs ArcGIS
Of course we will, After next monday.