Qgis help file

Working with Vector Data Working with Raster Data Working with Mesh Data Working with Vector Tiles Laying out the maps Working with GPS Data Authentication System QGIS processing framework Processing providers and algorithms Plugins Help and Support Mailing lists QGIS Users QGIS Developers QGIS Translations QGIS User groups IRC Commercial support BugTracker You can see how easy it is to visualize raster and vector layers in QGIS.

We will repeat this here, and you will see that QGIS also provides further command line options. QGIS supports a number of options when started from the command line. To get a list of the options, enter qgis --help on the command line. The usage statement for QGIS is:. You can start QGIS by specifying one or more data files on the command line. Command line option --snapshot.

This option allows you to create a snapshot in PNG format from the current view. This comes in handy when you have a lot of projects and want to generate snapshots from your data. Currently, it generates a PNG file with x pixels. This can be adjusted using the --width and --height command line arguments.

A filename can be added after --snapshot. Command line option --lang. Based on your locale, QGIS selects the correct localization. If you would like to change your language, you can specify a language code. Command line option --project.

Starting QGIS with an existing project file is also possible. Just add the command line option --project followed by your project name and QGIS will open with all layers in the given file loaded. Command line option --extent. To start with a specific map extent use this option. You need to add the bounding box of your extent in the following order separated by a comma:. Command line option --nologo. Map canvas refresh to debug rendering duration in the Log Messages panel.

Double click action in legend. Display classification attribute names in the Layers panel, e. This tab offers some options regarding the behavior of the Identify tool. Search radius for identifying features and displaying map tips is a tolerance distance within which the identify tool will depict results as long as you click within this tolerance.

Highlight color allows you to choose with which color should features being identified be highlighted. Buffer determines a buffer distance to be rendered from the outline of the identify highlight. Minimum width determines how thick should the outline of a highlighted object be.

Keep base unit to not automatically convert large numbers e. Here, you find a list of predefined scales. With the and buttons you can add or remove your personal scales. XML file. Note that you still have the possibility to remove your changes and reset to the predefined list. This menu allows you to create or update palettes of colors used throughout the application in the color selector widget.

You can choose from:. Project colors , a set of colors specific to the current project see Default Styles Properties for more details. New layer colors , a set of colors to use by default when new layers are added to QGIS. By default, Recent colors , Standard colors and Project colors palettes can not be removed and are set to appear in the color button drop-down.

Custom palettes can also be added to this widget thanks to the Show in Color Buttons option. For any of the palettes, you can manage the list of colors using the set of tools next to the frame, ie:. Add or Remove color. Copy or Paste color. Double-click a color in the list to tweak or replace it in the Color Selector dialog. You can also rename it by double-clicking in the Label column. This tab helps you configure general settings when editing vector layer attributes and geometry.

Suppress attribute form pop-up after feature creation : this choice can be overridden in each layer properties dialog.

Reuse last entered attribute values. Validate geometries. Editing complex lines and polygons with many nodes can result in very slow rendering. This is because the default validation procedures in QGIS can take a lot of time. GEOS geometry validation is much faster, but the disadvantage is that only the first geometry problem will be reported. Define Rubberband Line width , Line color and Fill color. Enable snapping by default activates snapping when a project is opened.

Show snapping tooltips such as name of the layer whose feature you are about to snap. Helpful when multiple features overlap. Enable snapping on invisible features. Show markers only for selected features. The next 3 options refer to the Offset Curve tool in Advanced digitizing. Through the various settings, it is possible to influence the shape of the line offset.

These options are possible starting from GEOS 3. You can define the Default font used within the print layout. Define the Grid spacing.

Define the Grid offset for X and Y. Define the Snap tolerance. Define Path s to search for extra print templates : a list of folders with custom layout templates to use while creating new one. GDAL is a data exchange library for vector and raster files. It provides drivers to read and or write data in different formats. The GDAL tab currently exposes the drivers for raster formats with their capabilities. This frame provides ways to customize the behavior of drivers that support read and write access:.

Edit create options : allows you to edit or add different profiles of file transformation, i. The parameters depend on the driver. The upper part of the dialog lists the current profile s and allows you to add new ones or remove any of them. You can also reset the profile to its default parameters if you have changed them. Some drivers eg, GeoTiff have some sample of profiles you can work with.

The button lets you add rows to fill with the parameter name and value. The button deletes the selected parameter. Click the Validate button to check that the creation options entered for the given format are valid.

Use the Help button to find the parameters to use, or refer to the GDAL raster drivers documentation. The Variables tab lists all the variables available at the global-level. It also allows the user to manage global-level variables.

Click the button to add a new custom global-level variable. Likewise, select a custom global-level variable from the list and click the button to remove it. More information about variables in the Storing values in Variables section. In the Authentication tab you can set authentication configurations and manage PKI certificates. See Authentication System for more details. Defines the Directory and a Size for the cache. Also offers tools to automatically clear the connection authentication cache on SSL errors recommended.

Use proxy for web access. Available proxy types are:. Socks5Proxy : Generic proxy for any kind of connection. Credentials of proxy are set using the authentication widget. Using proxies can sometimes be tricky. The Locator tab allows to configure the Locator bar , a quick search widget available on the status bar that helps you perform searches anywhere in the application. It provides some default filters with prefix to use:. Project layers l : finds and selects a layer in the Layers panel.

Project layouts pl : finds and opens a print layout. Active layer features f : searches for matching attributes in any field from the current active layer and zooms to the selected feature.

Features in all layers af : searches for matching attributes in the display name of each searchable layers and zooms to the selected feature. Spatial bookmarks b : finds and zooms to the bookmark extent. Settings set : browses and opens project and application-wide properties dialogs. Processing a : searches and opens a Processing algorithm dialog. Edit selected features ef : gives quick access and runs a compatible modify-in-place Processing algorithm on the active layer.

For each filter, you can customize the filter, set whether it is enabled by default or not. The set of default locator filters can be extended by plugins, eg for OSM nominatim searches, direct database searching, layer catalog searches.

Type your text to perform a search. By default, results are returned for all enabled locator filters but you can limit the search to a certain filter by prefixing your text with the locator filter prefix, ie. Click on the result to execute the corresponding action, depending on the type of item. Searching is handled using threads, so that results always become available as quickly as possible, regardless of whether any slow search filters may be installed.

They also appear as soon as each result is encountered by each filter, which means that e. This ensures that the UI is always responsive even if a very slow search filter is present e. The Advanced tab offers you in a single place, regardless your OS, means to manage these settings through the Advanced Settings Editor. After you promise to be careful, the widget is populated with a tree of all QGIS settings, which you can directly edit.

Be careful while modifying items in this dialog given that changes are automatically applied. Doing changes without knowledge can break your QGIS installation in various ways. The Processing tab provides you with general settings of tools and data providers that are used in the QGIS Processing framework.

More information at QGIS processing framework. A user profile is a unified application configuration that allows to store in a single folder:. GUI configurations and customization. By default, a QGIS installation contains a single user profile named default. But you can create as many user profiles as you want:. A new instance of QGIS is started, using a clean configuration. You can then set your custom configurations. As each user profile contains isolated settings, plugins and history they can be great for different workflows, demos, users of the same machine, or testing settings, etc.

You can also run QGIS with a specific user profile from the command line. When you encounter weird behavior with some functions in QGIS, create a new user profile and run the commands again. Sometimes, bugs are related to some leftovers in the current user profile and creating a new one may fix them as it restarts QGIS with the new clean profile. The project-specific options overwrite their equivalent in the Options dialog described above. In the General tab, the General settings let you:.

The path can be relative to the folder of the project file type it in or absolute. The project home can be used for storing data and other content that is useful for the project. You may prefer relative path when both layers and project files can be moved or shared or if the project is accessed from computers on different platforms. Note that checking this option can lead to performance degradation. Calculating areas and distances is a common need in GIS.

However, these values are really tied to the underlying projection settings. The Measurements frame lets you control these parameters. You can indeed choose:. These settings, which default to the units set in QGIS options but then overrides it for the current project, are used in:. The Coordinate display allows you to choose and customize the format of units to use to display the mouse coordinate in the status bar and the derived coordinates shown via the identify tool.

Finally, you can set a Project predefined scales list, which overrides the global predefined scales.