Qgis Label Expression

QGIS with OpenGeo Suite The label is set in the text symbolizer on lines 10-12, with line 11 determining what text to display, Finally, there are two added touches for label placement optimization: line 20 ensures that long labels. I have a dataset where I'm incrementing colour by a variable in the aes. …The first way we're going to add the shape files…is using the browser. There is a QGIS expression function which retrieves a single feature from another table: so the moment I zoomed, the labels totally lost their position and size relative to the polygons. Essen was the host city to our developer meet ups in October 2012 and 2014. Expressions -Fields and Values 8. Also, I want to use the expression code to only label for features where an attribute has a value. all the changes I made have disappeared. Check that Offset From Point is checked and then click the Data Defined Override next to the Offset X, Y boxes and choose Edit. Reviewed 2015-07-19. A label expression is limited to a single line of code unless you check the Advanced box on the Label Expression dialog box. So, lets imagine that way back at the beginning of our project we created a project level variable called @main_label_font:. However, you can switch to the standard labeling engine if you like. The Layer Properties dialog box appears. It acts almost like another application. QGIS already had the expression builder for the query window and the field calculator, however the code was very tied down to only work for those implementations, plus they didn. Objective of the Tutorial• To make a choropleth interactive map, as given in the picture, using open source QGIS mapping software. So here is a neat trick. You are also able to select Transparency level, Type. Go to label settings and add a rule-based label. A pop up menu appears. Using the Maplex Label Engine and a combination of the Contour Placement style, a label expression, and a halo symbol will allow you to create labels that ladder along the contours at specified elevations. We will create the expression in the box with the expression creator (button to the right) Select your Font, Style, Size, and Color of your label. Not to fear, expression functions are here. What’s new in QGIS 2. Now we are ready to perform our query on these attributes. 90) has a new feature “expression based labeling” which can be used to create conditional labels. Using Expression Labeling: Select the layer you want to label; Right click on the layer and select properties, now the property dialog will open. QGIS has a powerful tool called Print Layout that allows you to take your GIS layers and package them to create maps. Check that Offset From Point is checked and then click the Data Defined Override next to the Offset X, Y boxes and choose Edit. Choose Properties. I call the variant I describe here 'lollipop' labels because the 'callout line' is rendered with a decorative ball at the end. You will notice that it is added to the expression section at the bottom. The following tips will help you build your label expressions:. You can also convert strings to all lowercase in a text field using the. Directly drag and drop layers from ArcCatalog to QGIS windows to open in QGIS* Support for ESRI MapServer layers (*requires QGIS 3. Therefore, three new editing tools to manipulate text labels are now in the QGIS developer version: the move label tool drags text labels to a new position the rotate label tool is for interactive rotation of labels the label property tools opens a dialog that lets the user manipulate the data defined properties of a label (and also the text of. for users new to GIS and/or new to QGIS that wish to utilise the key functions of v2. A prior familiarity with basic QGIS capabilities is assumed. Choose Labels. Follow Along: Using Labels Instead of Layer Symbology¶. In the Layer Panel, mouse right click on the layer to be labelled, e. Expressions¶. QGIS doesn't have an official way to split labels up into categories, and until now I'd resorted to having two layers to render otherwise identical features. The main properties dialog is where the text (HTML or not) or the expression needed to fill the label is added to the Composer canvas. a comprehensive course for new and. GIS247 Guide to QGIS 2. Master over 170 recipes that will help you turn QGIS from a desktop GIS tool into a powerful automated geospatial framework QGIS is a desktop geographic information system that facilitates data viewing, editing, and analysis. The tool can be found under the Vector Selection tool in the Processing Toolbox (See figure 1). In July 2002 Gary Sherman in Alaska starting writing open source QGIS 0. QGIS Enhancement 59 (was 40): Aggregate functions for QGIS expressions Date 2016/04/29 Author Nyall Dawson (@nyalldawson) Contact nyall dot dawson at gmail dot com Version QGIS 2. Python script can be used in many parts within ArcGIS; label expression, attribute calculator, model builder or geoprocessing tools. Source: woostuff. GIS247 Guide to QGIS 2. If I use the plotmath bold it succeeds from inside the expression function:. una regola per ogni. GRASS modules can be run from QGIS GRASS Tools if QGIS was started from a GRASS shell or if a GRASS mapset was opened from QGIS. The Expressions feature are available through the field calculator or the add a new column button in the attribut table or the Field tab in the Layer properties ; through the graduaded, categorized and rule-based rendering in the Style tab of the Layer properties ; through the expression-based labeling in the Labeling core application ; through the feature selection and through. The scale bar can already be set to numeric to show the number value but what if it needs to be part of an existing label with other text. Merge: 88dc61503c c8aceb22ba Alexander Bruy 2017-09-12 Merge pull request #5167 from alexbruy/extract-by-expression [processing] add Extract by expression algorithm to QGIS 2. Using Expression Labeling: Select the layer you want to label; Right click on the layer and select properties, now the property dialog will open. Labels can be interpreted as HTML code: check Render as HTML. QGIS Specific Labelling I am using a shp file for all the lakes in the province and have a list of only key lakes that I need labels for (the list is still 500+) is there a way to label just these specific lakes from the list I have. This is now easy to make multiline label in QGIS, with concatenation in expressions. Click Select features using an expression. A label expression is limited to a single line of code unless you check the Advanced box on the Label Expression dialog box. None [1666] Processing Saga NextGen Provider. Create a new composer. It acts almost like another application. ArcGIS adopted it after version 9. Fixing the Labels. Follow Along: Using Labels Instead of Layer Symbology¶. QGIS is less well suited for making interactive web maps, although there are various plugins that facilitate this work. 12, I'm going to dig into how variables are scoped in QGIS and what layer level variables are available (you can read parts 1 and 2 for a general introduction to variables). una regola per ogni. lower() property. The tool can be found under the Vector Selection tool in the Processing Toolbox (See figure 1). But in QGIS, things go a little bit further… Basically, you can use coverage layer's attributes and geometry anywhere you can use an expression. Showing topics with label Expression builder. 0 Label with expression Lene Fischer. The latest QGIS development build (1. …The first way we're going to add the shape files…is using the browser. The Expression String Builder will appear. There's actually two ways you can go about doing this - with the first explanation being the easiest the second explanation being a bit more flexible. The next step is to control the position of the label around the points using trigonometry. 12 and making your workflow in QGIS easier. You can change fonts or you can insert blank space that is sufficient to hold a particular character string with plotmath phantom():. To set the expression used for a data defined property, use the setDataDefinedProperty method. This includes using them for data defined overrides in symbology and labelling. Come etichettare uno shapefile poligonale con più attributi in multi-linea e con formattazione testo diverso per ogni attributo. I have a layer with a number of polygons. For example, most of the points in the places layer refer to entire towns or suburbs, and the specific point associated with such features is not that specific on a large scale. 12, I'm going to dig into how variables are scoped in QGIS and what layer level variables are available (you can read parts 1 and 2 for a general introduction to variables). Expressions - QGIS. This article presents a rough idea of how one might mimic a non-contiguous cartogram using QGIS. One typical use case would be if you want to label only certain (high-level) road classes in your road layer. You are also able to select Transparency level, Type. Come etichettare uno shapefile poligonale con più attributi in multi-linea e con formattazione testo diverso per ogni attributo. That is what QGIS expression in the label expression is used for. QGIS doesn't have an official way to split labels up into categories, and until now I'd resorted to having two layers to render otherwise identical features. As a quick refresher, variables are a new feature in QGIS 2. The Select by Expression window has also been slightly redesigned. In 2011, I wrote "How to Label Only Selected Features in QGIS" which ends with the wish that Another "data defined setting" like "show this label (true/false)" would be more intuitive. This time, we will use them to create a dynamic data driven style, that is, a style that automatically adjusts to the minimum and maximum values of any numeric field … and that field will be specified in a variable!. 3 64bit was used to prepare the data for animated map visualization of Alaska's forest damage. Use the Area label expression to label the layer. Have I missed a setting or does this need an expression/code somewhere to create th linkage?. QGIS has a powerful tool called Print Layout that allows you to take your GIS layers and package them to create maps. QGIS 3: Layout expression to get all features of a layer within the current map view In a map layout template you can insert an expression which gets all feature's names of a certain layer, which are contained in the current layout's view/extent. I would like to know if it would be possible to have different fonts, one per line (or per item). I want to use XML embedded in the code to change label color based on attribution. QGIS, however, gives only pie charts and histograms, which don't satisfy in my case. Using this simple trick allows you to take advantage of all the possibilities which the QGIS labelling and expression engines allow! *Bonus points for the first person to use this technique along with data defined controls for animating the label colour/size!. QGIS doesn’t have an official way to split labels up into categories, and until now I’d resorted to having two layers to render otherwise identical features. TODO: Add screenshots. Not to fear, expression functions are here. One of those things is expression labelling, it´s one of those features that I use a lot at work and wanted to try out with QGIS 2. Of course this feature request is still valid, as it is about automatic wrapping, not wrapping with a manual line break. Next, click on the SQL Query button to essentially do a Definition Query for [Lin_typ] = "Major". Create another grid to show the labels in the centre of the visible grid cells. However, there is a way around this issue using Trigonometry and editing the layer's Attribute Table. subscripted text appears on the far right). QGIS' Composer has the ability to create an "Atlas" built-in. All example data and project files are included. In addition there is always a latest release. 8¶ This release contains new features and extends the programmatic interface over previous versions. Click Select features using an expression. 0 aka QGIS-master. Is there any resource recommendations in general for getting past the basics of QGIS and going into the deep dark secrets? Specifically in relation to expression coding for labeling, queries, etc. The latest QGIS development build (1. You can now insert a URL, a clickable image that links to a web page or something more complex. 0 and I have some issues with the polygonize tool. It acts almost like another application. 0 features plus. You will need a file of postcodes with easting and northing values in plain text format in order to complete this tutorial. tra queste reputo straordinaria la Selezione per espressione (select by expression) in quanto è molto potente, didattico e mette a disposizione tutte le funzioni del calcolatore di campi; in questo blog post esploreremo alcune delle infinite possibilità di questo algoritmo. From titles to lowercase to uppercase…. Klas Karlsson 13,008 views. easy to use, add label to map, Qgis easy custom labeling, qgis multiple labels, rule based labeling, label with expression qgis. QGIS can be used to export data to a mapfile and to publish them on the Internet using a webserver with UMN MapServer installed. Python has a simple solution to capitalize the first letter in a text field. Day 24: Set a #QGIS map layer to the "Blocking" label mode to push other map labels away from features in that layer. This time, we will use them to create a dynamic data driven style, that is, a style that automatically adjusts to the minimum and maximum values of any numeric field … and that field will be specified in a variable!. In the combo box, select Show labels for this layer. for users new to GIS and/or new to QGIS that wish to utilise the key functions of v2. Modifing Labeling with expressions and scale limits. Basti usare l' etichettatura basata su regole. tra queste reputo straordinaria la Selezione per espressione (select by expression) in quanto è molto potente, didattico e mette a disposizione tutte le funzioni del calcolatore di campi; in questo blog post esploreremo alcune delle infinite possibilità di questo algoritmo. For example, most of the points in the places layer refer to entire towns or suburbs, and the specific point associated with such features is not that specific on a large scale. For example, an Arcade expression might be created to derive a yearly sales figure for individual sales territories by summing the value of monthly sales fields. Expressions make it easy to limit labels to important features. It can be accessed using the Expression Builder, the Select By Expression, the Geometry generator symbol layer option, the Field calculator or the Data defined override tool. QGIS Tutorials and Tips In the Select By Expression window, expand the Fields and Values section and double-click the pop_max label. GIS Exercises Lab 9: Buffering and Overlay 8 Use Select by expression to find those areas with insd_lbuf=1 and insd_rbuf = 1, and assign them the number 1 using the Field Calculator assign then to a field called "in_both" (previous exercises, or see graphic below). Open the file with QGIS : Add Delimited Text Layer (Layer Add Delimited Text Layer) Select the. With v2 the user had to add specifically named fields to each layer to enable each icon in the relevant toolbar. You can now insert a URL, a clickable image that links to a web page or something more complex. It is easy to modify the menu and add new modules because both the menu and the modules are defined in XML configuration files. This is made possible by the use of "QGIS label expression" command. However, there is a way around this issue using Trigonometry and editing the layer's Attribute Table. I found this discussion circa 2005 of a similar issue but the work around that they offer doesn't translate to my application in ggplot2. The Expression String Builder will appear. For example, you might use the bold formatting tag to make the first line bold in a stacked, multiline label. Go to label settings and add a rule-based label. The basics are you can use code and expressions in QGIS to draw Geometry. For the following examples the Regions layer of the QGIS sample dataset is used and selected for Atlas Generation. 12 and making your workflow in QGIS easier. You will notice that some rows in the attribute table are now selected. It acts almost like another application. Following up on the example used in my previous post, we can simplify. Easier Conditional Labels in QGIS. 3391' 45 deg. 12 which allow you to create preset values for use anywhere you can use an expression in QGIS. 0, the spatial queries operation can be performed with a tool called Select by Location. 90) has a new feature “expression based labeling” which can be used to create conditional labels. The label window also changes and shows the count of selected features. Expressions¶. I have line feature and want to add a foot tick mark and a deg symbol to label the label as of now shows "dis" || "Azimuth" 339045. That way, most layers and map composer items properties can be controlled by a single coverage layer. The QGIS Atlas is a true open source technique to generate hundreds of maps in minutes. Expression based labeling now in QGIS and the new expression builder. 2 Valmiera All of the QGIS 2. 18 : Part 2. By default, ArcGIS Pro uses the Maplex Labeling Engine with its sophisticated label placement capabilities. QGIS plugins web portal. I want to use XML embedded in the code to change label color based on attribution. 8, there is a new option for users to add their own python function in the Field calculator. The Layer Properties dialog box appears. 10 or later) Over the remainder of 2019, we’ll be hard at work further improving SLYR’s support for MXD document conversion, and adding support for automatic conversion of ArcMap print layouts to QGIS print layouts. However, you can switch to the standard labeling engine if you like. all the changes I made have disappeared. tra queste reputo straordinaria la Selezione per espressione (select by expression) in quanto è molto potente, didattico e mette a disposizione tutte le funzioni del calcolatore di campi; in questo blog post esploreremo alcune delle infinite possibilità di questo algoritmo. Marker is a point on the map which is not a point feature. Right click the points layer and choose: Properties - Labels - Placement. Expressions are a kind of mini-programming language or SQL-like language found throughout different QGIS functions to select features. Follow Along: Using Labels Instead of Layer Symbology¶. Python has a simple solution to capitalize the first letter in a text field. See how QGIS is rapidly surpassing the cartographic capabilities of any other geoware available today with its data-driven overrides, flexible expression functions, multitudinous color tools, blend modes, and atlasing capabilities. GIS247 Guide to QGIS 2. However, there is a way around this issue using Trigonometry and editing the layer's Attribute Table. 90) has a new feature “expression based labeling” which can be used to create conditional labels. I need a Regex expression which won't accept repeated words (a-z). Using VBScript to Build Complex Labels in ArcGIS Continued from page 51 map so the value of the variable FindLabel will need to be set inside the function. Check that Offset From Point is checked and then click the Data Defined Override next to the Offset X, Y boxes and choose Edit. In the Select By Expression window, expand the Fields and Values section and double-click the pop_max label. Query expressions use the general form that follow a Select * From Where clause (for example, the part of the SQL expression that comes after SELECT * FROM WHERE). 18, using basic label settings, to place and orient a dip label next to a dip and strike symbol. ArcGIS adopted it after version 9. Klas Karlsson 13,008 views. The emphasis on this release has been very much on polish and performance - we have added many new features, tweaks and enhancements to make the user interface more consistent and professional looking (and hopefully easier to use). Press Browse button. lower() property. The new mask plugin is available in its 1. Other projects will be welcome to add their own example exercises as well. How to use Function Editor in QGIS Field calculator JUNE 05, 2015 analysis howto python qgis In QGIS 2. Labels can be interpreted as HTML code: check Render as HTML. “Labels” tab or the “Labels” button on the top menu. Tutorial 4 - Using QGIS to map postcodes. Objective of the Tutorial• To make a choropleth interactive map, as given in the picture, using open source QGIS mapping software. In the placement properties use data defined settings and use the expression X and Y. Using this simple trick allows you to take advantage of all the possibilities which the QGIS labelling and expression engines allow! *Bonus points for the first person to use this technique along with data defined controls for animating the label colour/size!. QGIS Enhancement 59 (was 40): Aggregate functions for QGIS expressions Date 2016/04/29 Author Nyall Dawson (@nyalldawson) Contact nyall dot dawson at gmail dot com Version QGIS 2. GIS247 Guide to Mastering QGIS 2. The idea would be to have a concept of “label layer” that could then be hidden by others, or even made partly transparent. Tags and tag attributes used in field values do not need to be surrounded by quotes, so the following are valid values for a label field: Rochester C Colorado. I´ve tried to insert a HTML in the label-expression. 18 : Part 1. QGIS has a powerful tool called Print Layout that allows you to take your GIS layers and package them to create maps. I render a some bus lines maps using QGIS Map Composer, and i want to much large scale as possible, and i need to optimize label placement. Go to label settings and add a rule-based label. upper() returns a copy of a strong with all the cases characters converted to uppercase. For this the labelling must be activated with the certain attribute. I do not think it is the presence of expression, although you don't say exactly what it is that you are seeing so it's difficult to be sure. A prior familiarity with basic QGIS capabilities is assumed. A simple SQL expression. Using Expression Labeling: Select the layer you want to label; Right click on the layer and select properties, now the property dialog will open. Basic label placement choices are also available from the ribbon. With a little bit of python programming, you can define your own functions that can be used within the expression engine. Change log for the next release of QGIS 2. Then saved the edits, saved the label layer, and closed the map. For example, an Arcade expression might be created to derive a yearly sales figure for individual sales territories by summing the value of monthly sales fields. TODO: Add screenshots. , which says food labels should not be false, misleading or. The emphasis on this release has been very much on polish and performance - we have added many new features, tweaks and enhancements to make the user interface more consistent and professional looking (and hopefully easier to use). Lets say you wanted to access the scale of a composer map to make it part of a label. Labels can be used to emphasise and name places on the map and to explain things verbally which can't be explained with graphical elements” In this module, we will look at how to use labels. 1 (pan, zoom, draw, line colors) (releases with pets on splash screen) January 2009 - Quantum GIS 1. My data is Categorized. For this the labelling must be activated with the certain attribute. Based on layer data and prebuilt or user defined functions, Expressions offer a powerful way to manipulate attribute value, geometry and variables in order to dynamically change the geometry style, the content or position of the label, the value for diagram, the height of a composer item, select some features, create virtual field. Right click the points layer and choose: Properties - Labels - Placement. View all issues; label properties will not saved to project files (buffer and background) QGis crashes due to conflicting. I am using QGIS Desktop 3. easy to use, add label to map, Qgis easy custom labeling, qgis multiple labels, rule based labeling, label with expression qgis. QGIS 3: Layout expression to get all features of a layer within the current map view In a map layout template you can insert an expression which gets all feature's names of a certain layer, which are contained in the current layout's view/extent. Number Format by Expression by akumar_c. 0 version on the QGIS official repository of plugins. Tutorial 4 - Using QGIS to map postcodes. The properties of a symbol layer, such as size or rotation, can be defined on a per-feature basis using an expression. substr(osm_name, 0, (clazz = 11 or clazz = 13 or clazz = 15 or clazz = 21)*-1) to. One of those things is expression labelling, it´s one of those features that I use a lot at work and wanted to try out with QGIS 2. By default, QGIS labels the features rather randomly:. Check that Offset From Point is checked and then click the Data Defined Override next to the Offset X, Y boxes and choose Edit. QGIS mapping interface is called 'Print Composer'. Next, click on the SQL Query button to essentially do a Definition Query for [Lin_typ] = "Major". That is what QGIS expression in the label expression is used for. I render a some bus lines maps using QGIS Map Composer, and i want to much large scale as possible, and i need to optimize label placement. Labels can be used to emphasise and name places on the map and to explain things verbally which can't be explained with graphical elements" In this module, we will look at how to use labels. The full power of normal label and rule expressions can now be used for label properties. QGIS can add labels automatically but their placement isn't always as you'd like it. “QGIS can display labels based on any attribute or expression. This tutorial will discuss how to create contour lines in QGIS. With a click on "Edit…" the expression string editor opens, which some of you should know from the field calculator for example. Expressions are a kind of mini-programming language or SQL-like language found throughout different QGIS functions to selected features. User defined expression functions for QGIS Posted on November 10, 2012 November 12, 2012 by Nathan Ever since I added expression based labels , including the new expression builder UI, something that I always wanted to add is the ability to define custom user defined functions in Python (or C++) and use them in an expression. The modules work with GRASS data only. for users new to GIS and/or new to QGIS that wish to utilise the key functions of v2. You can also make use of QGIS finer grained querying power, using the EXPRESSION tool user interface, or by running your own custom Python scripts with the same operators and functions. I am a big fan of label expressions but since the label expression does not seem to be working for you, why don't you try Label Classes. Changelog for QGIS 2. lower() property. If the feature you are tracing is very complex, then choose to snap and add a vertex manually at key points around the object. QGIS uses SQL-like expressions to perform queries. Come etichettare uno shapefile poligonale con più attributi in multi-linea e con formattazione testo diverso per ogni attributo. QGIS will divide up your layout into layers, so you should toggle them on and off to see which one is which. CSV with Browse 4. QGIS is a free, open source, cross platform (lin/win/mac) geographical information system (GIS) - qgis/QGIS. The Snapping options dialog box appears. Klas Karlsson 13,008 views. The aim of this post is to describe a method for labeling of a subset of features within a layer using new labeling functionality. You will notice that it is. The next step is to control the position of the label around the points using trigonometry. 0 you find the setting "data defined/show labels" at Labels -> Rendering -> Label options. Expressions are a kind of mini-programming language or SQL-like language found throughout different QGIS functions to selected features. I'd like to write an axis label over two lines with an expression() statement. Klas Karlsson 13,008 views. Now we are ready to perform our query on these attributes. 9 work? From Mapbox's manual: "Within a layer, styles can be broken up into I also want to place it as a point label, so I use the shield-placement function. In the Label with field, click the Expression icon. It just a graphic on the map that can be used to mark a location. For exemple : change data defined X and Y. Call out labels are a handy cartographic instrument for attaching labels to features on the map where you want the label to be offset from the feature being labelled. This article presents a rough idea of how one might mimic a non-contiguous cartogram using QGIS. How to use Function Editor in QGIS Field calculator JUNE 05, 2015 analysis howto python qgis In QGIS 2. However, it is not directly possible in QGIS 2. One important use of expressions is to control labels. I call the variant I describe here 'lollipop' labels because the 'callout line' is rendered with a decorative ball at the end. 0 Dufour All of the Atlas plugin features Integrated into QGIS core Feature filtering Feature sorting Fixed scaling File name expression Improved dynamic labels 7. If an expression is already available for the layer, you can use it for labeling. The labels are under a column called Street. Now I open the map again, and none of the labels is there. an intermediate level course that follows on from Part 1 to take QGIS users further with the software. 0 you find the setting "data defined/show labels" at Labels -> Rendering -> Label options. For those who know how powerful QGIS can be using data defined widgets and expressions almost anywhere in styling and labeling settings, it remains today quite complex to store custom data. So I’m going to draw leader lines from my label to my polygon with some code (that I copied from Kartoza’s example – Hey to Kartoza). The Select by Expression window has also been slightly redesigned. The syntax QGIS uses for 'if/when' is 'CASE/WHEN/THEN/END'. They are useful when constraints of space force a label to be moved away from the feature. But, in the new, excellent expression based labeling from Nathan Woodrow, I realized one can use an SQL CASE statement. Selecting this attribute will label each spot with its "Analysis Name. The following tips will help you build your label expressions:. That way, most layers and map composer items properties can be controlled by a single coverage layer. Source: woostuff. This is made possible by the use of "QGIS label expression" command. QGIS can be used to export data to a mapfile and to publish them on the Internet using a webserver with UMN MapServer installed. Choose Labels. 90) has a new feature "expression based labeling" which can be used to create conditional labels. Based on layer data and prebuilt or user defined functions, Expressions offer a powerful way to manipulate attribute value, geometry and variables in order to dynamically change the geometry style, the content or position of the label, the value for diagram, the height of a composer item, select some features, create virtual field. location of businesses and the placement of. Using VBScript to Build Complex Labels in ArcGIS Continued from page 51 map so the value of the variable FindLabel will need to be set inside the function. You will notice that it is added to the expression section at the bottom. New label tools in QGIS In cartography, it is a frequent operation to set labels to fixed positions, together with the position of the fix point (left/middle/right, Top, Half, Bottom) that is kept constant in case of font change, rotation or zoom. When you need to perform algebraic operations with two or more rasters you often have to ensure that these rasters have the same extent, otherwise the operation either won't be allowed (in SAGA for example) or you will. Variables to the rescue! As you may recall from part 1, you can reuse variables anywhere in QGIS where you can enter an expression. A “Calculate by Expression” option allows for updating existing batch table cells using the results of a QGIS expression. I have a dataset where I'm incrementing colour by a variable in the aes. Expressions are a kind of mini-programming language or SQL-like language found throughout different QGIS functions to select features. I am trying to change the font size of the feature labels based on attributes from a field. Because of its support for viewing PostGIS data and strong cartographic capabilities, the two are often found paired together. The emphasis on this release has been very much on polish and performance - we have added many new features, tweaks and enhancements to make the user interface more consistent and professional looking (and hopefully easier to use). These expressions can freely utilise other parameter values from the input batch rows, making it easy to craft the exact output file name you desire based on the other columns values in a batch row. Current and future developments, cartographic possibilities (with expression support; from QGIS 2. QGIS uses SQL-like expressions to perform queries.