If the friends of gvSIG They keep their promise, next Monday 27 of July we will have the stable 1.9 version. For now the testing has been great, according to the volume that is perceived in the Distribution lists. While Monday arrives, by the time I hope to have the satisfaction of congratulating the fulfillment of the word, at the expense of the safe pauses that the developers must take, let's take a look at Quantum GIS like a bird of prey.
QGIS was developed in C ++ using Qt toolkit, runs on Windows, Mac and Linux. The project arises in May from 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 have a corporate taste (it sells) when it comes to offering it. Aspect 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 consolidated, very good so as not to duplicate efforts. When starting QGIS and not finding it installed, raise an alert; in this case I am doing a review without including Grass. When wanting to load a set of Grass data, because it was not installed the application was closed, so I do not recommend using it without installing both tools.
Shortcuts, A good number of commands have a letter assigned, so that you can load the function 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 the keyboard.
The overview, in the left panel there is a map that shows the deployment area, with synchronization in both ways. Very useful, you can choose which layers you want to see in the overview, and you can also drop them as a floating window to 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 handling of width is of simple drag not only in the left panel but in the inferior one.
The bottom panel, when displaying the attribute table, it appears in the area, but it can also be floating. Very functional, with options to zoom to the selected rows and change the width of columns with a simple mouse drag. Also in the lower frame has the functions of search and select, similar to how it has Manifold GIS, 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 Plugins, Like any gpl application, its gain is in the plugins that the community is slowly doing (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 sight aids like north, scale and copyright, comma-delimited text, have 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 issue. Similar to what happens with gvSIG and Sextante although Grass's maturity 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 functions, like other tools, you can create spatial bookmarks, groups of layers, layers have minimum and maximum zoom control, easy to add coordinate systems and projection; in case of shp layers, if they have prj, Qgis rescues this information. A lot of processes include progress bar, which we think is very good.
It is very interesting how the attributes of the objects are configured, since 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 it to other layers. This table is also floating and you can adjust its width and height 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 you can convert data from other formats via the OGR converter. Additionally vector layers via WFS and PostGIS. Rescatable, 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 can be done through OGR shape files or Grass. The projects are saved as XML with qgs extension, where the conformation of layers is saved in gvSIG style.
Regarding the edition of data, in the properties of the project are stored specifications such as coordinate system, units, precision of decimals, enablement of topological editing, permission or limitation of superposition of polygons in the same layer and conditions of snap (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. Again, 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 after I load Grass's editing tools. Nor does there seem to be a track if several are editing a layer simultaneously, who wins first. ugh!
For fast exit purposes, there is an option to save the view as an image, and a plugin for fast printing, but unlike gvSIG, it does not have an ArcView style layout control; but a print composer that seems to me somewhat taken from the hair, although it allows to load dataframes, labels, boxes and symbols, and you can create several compositions for a project, I did not find how to save them as templates; the manual says that it is possible. I suppose that in the plugins of Grass there are better things for these purposes.
Quantum gis vs ArcGIS
Of course we will, After next monday.