Qgis Create Polygon From Lines

0 with the Split Feature command. When moving a vertex, all features that share that vertex are updated. 0 with Visual Studio 2010 How to create regular grids in QGIS Future trends in geospatial information management Creatubg TINs with structure lines in GRASS. Back in the main QGIS window, you will see one feature highlighted in yellow. Polygons can be created from a file that contains the points (Longitude and Latitude) that make up the vertexes of each polygon boundary, and the order in which to draw them. This will optimize the editing process of the layers. How to create lines from polygons? Yes, the Chopper breaks a polygon into lines if you set 2 or 3 to the "Maximum Vertices" parameter. ORIGINAL DATA Merge_Patch. Since Tableau allows us to create our own custom map elements from Points, Lines or Polygons, we will create a custom LGA polygon boundaries map of Kaduna state. Generate points (pixel centroids) inside polygon¶. The recipes can be tried in any order but it is recommended to go through the Getting started section first. If you wish to create intermediate points along the line you will need to use an alternate plugin. Snapping is performed to all map vertices - points from the Point vector layer and all Line and Polygon members. http://changelog. lines and polygons by GPS device was organized in the first half of the second day, after which the practical part was continued in the training room. You can the save your profile in a number of useful formats (. The plugin will create a new point file which contains all vertices along the line. Or create series of points on polygon, add buffer to them, produce line from intersection of polygons from buffer. When QGIS starts, you are presented with the GUI as shown below. How to create lines from polygons? Yes, the Chopper breaks a polygon into lines if you set 2 or 3 to the "Maximum Vertices" parameter. Notice that in QGIS you can set transparency at color level everywhere (or almost everywhere) there is a color to select. date, id number etc). Click on a series of places on the map to form a polygon. For example, you could merge the individual islands that make up Hawaii to create a multipart polygon feature. A new layer called Hub distance should now display lines to hubs, indicating the nearest bus stops to each polygon in the opt_1 layer. We are going to use the polygonize function from the Shapely library for Python. Polygons are created from a file that contains the points [in Longitude and Latitude] that make up the ‘point-extent’ of each boundary, and the order in which to draw them. The first layer sets the vertices (nodes) along the polygon line as visible, the second makes the polygon display as an outline only. (2) To avoid polygon overlaps, when a new polygon is digitised. Zoom into the creek at the south-western edge of the code polygon. Launch QGIS; Load the data layer. ,Google earth images, IRSdata,LANDSAT data. Lines / Polygons to display border. TODO: Add screenshots. The real power of mapping tools like QGIS is the ability to layer data to visualize spatial relationships. QGIS is an open-access. Split Sub Divide polygon layer using QGIS - Shapefile, kml, GeoJson Sub divide or split polygon in multiple parts. Advanced Layer Styles in QGIS. The data I am using is a … Continue reading Creating Animated Flight Lines in QGIS. What happens to the attributes from the line to polygon? Amazing what the online help tells. Highlight the folder that will contain your new shapefile. The web site is a project at GitHub and served by Github Pages. Thus the title of the feature request, as it might be a possible solution to allow the transformation of such rings into polygons. Create Tableau polygons from shapefiles using QGIS Before you follow the steps in this section, the coordinates in your shapefile should already be in the form of decimal latitude and longitude units, specifically using EPSG: 4326, WGS 84. In the last line, there is a check that start and end node ID should be different in order to avoid zero-length lines. In this image the red lines are our postcodes, and the yellow area is the highlighted Glasgow City polygon. New symbology has been around for quite a while now, but the last weeks have seen some great new additions to this functionality. ,Google earth images, IRSdata,LANDSAT data. Making a Map with QGIS Introduction. This tutorial is designed as. Hello Folks if you are looking for QGIS 3. As a consequence, the python plugin fails to build many polygons (they become just a bunch of lines) and represent all roundabouts as polygons (those must be represented as [closed] ways, otherwise QGIS cannot render them with a border as osmarender and mapnik). line vs polygon) Feature request #6188 : Let the user fine tune stretching values in raster properties/style. Patrick’s”. QGIS functions as geographic information system (GIS) software, allowing users to analyze and edit spatial information, in addition to composing and exporting graphical maps. With just a few simple steps you can pass the KML files to shapefiles, using QGIS. UNIONIt is a geometric combination of two or more coverages. …Exploring the edge and fills can help…to add these types of layer to your map…without hiding the layers underneath. For example creating buffer or clipping the polygon I will be using the Geoprocessing tools to demonstrate some of the task that we might use every day while editing. For polygons, the first coordinate pair (point) on the first line segment is the same as the last coordinate pair on the last line segment. ArcGIS Help 10. Before you start a editing session in QGIS, make sure you set the right snapping options. shp data layer. QGis can convert raster polygons into vector polygons (raster > polygonizer). Hi, I'm battling finding an easy way to cut some lines with a polygon boundary, and then deleting the line portions that are OUTSIDE the OSGeo. Start QGIS by typing: “QGIS” at a command prompt, or if using precompiled binary, using the Applications menu. Set the following:. Here's a screenshot for a single layer. Polygon Outlines in QGIS I had an effect of an outline around the grid in the Glasgow Commercial Property Density heatmap. By their nature the contours are polyline features, but many GIS users want to represent the area closed between two adjacent contours with a polygon. After describing the feature to polygon tool, there is a note that says the keep attributes button does not work and should not be used. QGIS Basics 02 - How To Create Polygon Layer and Add Polygons Reviewed by world on February 05, 2019 Rating: 5 QGIS Basics 02 - How To Create Polygon Layer and Add Polygons This Video will show how to create a polygon layer and polygon. Press the Enter button to finish Drawing and create the Polygon, turning it into a Solid, Colored image. The outside boundary of the output Thiessen polygon feature class is the extent of the point input features plus an additional 10%. Making a Map with QGIS Introduction. 1 - Converting points to lines or polygons (Defense Mapping). 2 and Create points within th. Save it on a new location. The output layer type is Line, not PolyLine. The ESRI Shapefile is a widely used file format for storing vector-based geopatial data (i. LAB 9: Buffering and Overlay in QGIS line, or polygon input, and creates Buffering in QGIS Create a new QGIS project and add the roads. Now I wish to know how to clip a contour line shape file with the polygon I have created in SAGA. Basically, I have some points on a network and I need to create new points on the network that are 1 m away from that point. The procedure to create a point or line is the same as a polygon in which the polygon is comparatively the most difficult of the three. They are useful when constraints of space force a label to be moved away from the feature. Here in this article QGIS 3. After that user have to provide CRS for the new shape file. These layers can be used in QGIS as they are or saved in another format, such as a shapefile. Enhanced: 2. Here's a comparison of the two:. Then convert the buffer polygons into lines (Vector > Geometry Tools > Polygons to lines) Then convert. Once the file is created it is fairly straight forward to create custom polygons in Tableau. Click on the Split Features tool (the scissors and line tool selected above) and click on the start point of the line that will be used to bisect the polygon using the left mouse button. This is a rather important function for our project, as one of our requirements is that the user knows ArcGIS. With just a few simple steps you can pass the KML files to shapefiles, using QGIS. View and analyse Fusion tables data on Google maps. In the last line, there is a check that start and end node ID should be different in order to avoid zero-length lines. Labels with callout lines in QGIS. But we can't use it with the downloaded data. click2shp is a browser-based GIS shapefile creation tool. Not the case in real life, but a good approximation. In this QGIS tutorial I will use a real-life geophysical survey to detail how I use QGIS to create polygon grids, how I orientate them to fit the area of interest and how I export the grid as points to use with a GPS or Total Station system. QGIS already allows to create rings, i. 0 Enhancement to PIP short-circuit for geometry extended to support MultiPoints with few points. Vector data are often stored as a ‘shapefile’. Split Sub Divide polygon layer using QGIS - Shapefile, kml, GeoJson Sub divide or split polygon in multiple parts. http://changelog. Using ‘Marker Placement’ options in ‘Marker Line’, we can now create fancy arrows pointing in or against line direction. Patrick’s”. The Shapefile format does not only allow you to easily manage point, line and polygon layers in QGIS but it also gives you a user friendly interface to manage the attributes of your vector data in QGIS. There is a collection of plugins ready to be used, available to download. Converting points to lines to polygons and back – QGIS Sometimes your data is vector formatted (point, line, or polygon), but it is not the right kind of vector for a particular type of analysis. In a previous post (QGIS Trace Edit Tool) I discussed how to use QGIS' trace edit plugin to create a polygon adjacent to an existing polygon while ensuring that it is topologically correct. 2 and Create points within th. QGIS is quite a good package for this type of project. - Use "features to raster" or "polygon to raster" tool. You can say that this is being overrated, but check the differences in the following images. Lines Polygons Polygonize converts lines to polygons Perfect Polygons in QGIS Author: An Introduction to the Polygonize Tool Created Date:. Here the participants practically learned how to tethering GPS data into QGIS software and how to utilize, edit and analyze by the QGIS the data collected by GPS device. I have an interesting problem in QGIS, I have a vector layer of points (shown in purple) and a layer of polygons (green) with a number of metadata attributes attached (i. Use this rule when polygon boundaries should be coincident with another line feature class or subtype. …First we need to add the DEMs to the map. The lines have been split where they were intersected by polygons, and each line feature has been assigned the attributes of both original layers. For example creating buffer or clipping the polygon I will be using the Geoprocessing tools to demonstrate some of the task that we might use every day while editing. Then define File encoding. You will then be prompted to confirm: The. Elevation data (DEM) is also distributed as raster files. We will start with some raster files and use a nice GRASS tool for the main work. The QGIS provides a number of plugins when you are working with polygons. For this case, create a folder in US Counties called Singleparts. There are 444 CD features and about 33k ZCTAs. LAB 9: Buffering and Overlay in QGIS line, or polygon input, and creates Buffering in QGIS Create a new QGIS project and add the roads. holes in larger polygons. Start QGIS using the Start menu or desktop shortcut, or double click on a QGIS project file. Before creating new map layer go to browser panal. 0, we added the ability to extend an existing line feature by clicking a “+” indicator at the start or end of line features when using the node tool. After that user have to provide CRS for the new shape file. Converting points to lines to polygons and back - QGIS Sometimes your data is vector formatted (point, line, or polygon), but it is not the right kind of vector for a particular type of analysis. Advanced Layer Styles in QGIS. In QGIS, the data need to be the data same type (i. In this lesson you will install QGIS software, download geospatial files like shapefiles and GeoTIFFs, and create a map out of a number of vector and raster layers. This tutorial is designed as. Various vector layers and tables (OGR, SpatiaLite, PostGIS, MSSQL Spatial or Oracle Spatial) can be edited in QGIS. A plugin called Profile from Line appears to do this. Callouts, sometimes called leader lines, are lines between labels and features on a map. I will outline the steps to create such a map. Specify Polygon Layer if digitizing your own coverage. After the SLD's have been saved and used in QGIS to create the styling the layers look like this: The following items must be changed by hand: - Enkelbestemming, the thickness of the polygon outline must be reduced to 1, - Bouwaanduiding, the thickness of the polygon outline must be reduced to 1,. Polygons can be created from a file that contains the points (Longitude and Latitude) that make up the vertexes of each polygon boundary, and the order in which to draw them. Add the existing line feature and the newly created polygon layer to a map document. Today we are going to learn how to convert polyline to polygon on QGIS. The python script will create an additional window within QGIS that has additional functions for editing the plot position and other parameters such as line thickness, axes and labels. These are all ways i would approach this, its nothing perfect but better than nothing. Exercise using QGIS. In the end, you will have something that looks like the image below. You can also click-and-drag to create frequent nodes, which makes a smoother boundary to your polygon. lines that share an endpoint) into a smaller set of longer lines. Digitizing Map Data¶ Digitizing is one of the most common tasks that a GIS Specialist has to do. Implements a processing algorithm to calculate the pole of inaccessibility for a surface, which is the most distant. Digitize the inner ring in the end. In the last line, there is a check that start and end node ID should be different in order to avoid zero-length lines. QGIS: Azimuth and Distance Plugin This tutorial walks you through using the QGIS Plugin Azimuth and Distance Plugin to key in US Survey data to generate lines to denote property boundaries. We will add polygon, field and other attributes. Converting points to lines to polygons and back – QGIS Sometimes your data is vector formatted (point, line, or polygon), but it is not the right kind of vector for a particular type of analysis. You could create a polygon topology for the different feature types (i. Click OK to generate the lattice point labels and polygons. …For example, you can have a continuous contour line…that represents 20 feet above sea level,…along that line. For example, you might need to create parcel polygons from lot lines, lakes from shorelines, or street polygons from pavement lines. ORIGINAL DATA Merge_Patch. Polygons are created from a file that contains the points [in Longitude and Latitude] that make up the ‘point-extent’ of each boundary, and the order in which to draw them. All use geodesic math to calculate the shapes. But we can't use it with the downloaded data. Merging can be based on one of these two criteria: Length: a segment is merged to its longest neighbor. Easily create point maps: convert shapefile points to polygons in just 3 steps The free QGIS software can be used to easily convert points in shapefile maps to polygons. Tables can be added to QGIS by simply dragging them down into the Layers. 2 allows for some rather powerful improvements to multi-map compositions! Drawing polygon borders only inside the polygon. Add the existing line feature and the newly created polygon layer to a map document. • These require geo-referenced base data. I'm afraid the only you can do that I can think of is to digitise a new layer of polygons. The shapefile looks like this. QGIS algorithm provider implements various analysis and geoprocessing operations using mostly only QGIS API. However, QGIS interprets all CSV columns as strings by default, which is a problem if you intend to use numbers to conditionally style your map. However, to generate concentric multi-ring buffers you can use the QGIS plugin tool named – Multi Ring Buffer. line polygon. But before we are discussing about drawing contour lines in QGIS, let's start talking a little bit about the concept of contour line, what contour line definition is, contour lines characteristics and and how the method in drawing contour line. lines of the Polygon begin to form. com to discuss licensing arrangements for your organisation! Alternatively, send us an email if you'd like to. GE-Path allows you to take point data, either from a KML file, a spreadsheet, or entered manually, and create paths and polygons from them. Generates a point vector layer from an input raster and polygon layer. Today we are going to learn how to convert polyline to polygon on QGIS. Hi, I'm battling finding an easy way to cut some lines with a polygon boundary, and then deleting the line portions that are OUTSIDE the OSGeo. Let’s throw in some curved arrows!. Patrick's". This example demonstrates use of several different R packages that provide functions for reading and/or writing shapefiles. Select the type of shapefile you wish to. I tried it with the "Lines to polygons" tool (Vector > Geometry Tools > Lines to polygons), but it didn't work correctly. In Target and Oasis montaj, sometimes you need to create a polygon file for windowing (i. The perpendicular bisectors for each triangle edge are generated, forming the edges of the Thiessen polygons. Instructions provided describe how to symbolize polygon outlines with either a cased line (a line with fill color and a different outline color), or a dashed/dotted line in ArcGIS 9. - Use "features to raster" or "polygon to raster" tool. Toggle editing for the 2d_bc_M01_002_L layer and then select the Capture Line. To minimize processing time you could create copies of these layers, modify them by deleting attribute columns, and run the process on this modified layer. A: Create a raster from your polygons. Discover ideas about Fishnet Geospatial / GIS. Snapping is performed to all map vertices - points from the Point vector layer and all Line and Polygon members. Thanks to whoever fixed the right-click crash bug one hour after I reported it! I was given a bitmap file representing the new boundaries of regions we are supposed to be working on for a project. About creating lines and polygons. Some of the common plugins allow you to count the number of vertices of simple and multi part geometry, calculate the azimuths and distances of selected feature and figures and also the convergence factor, calculate the total sum of all the line lengths of each. For polygon creation there is a Create polygon button on the OSM Feature widget. Instructions provided describe how to symbolize polygon outlines with either a cased line (a line with fill color and a different outline color), or a dashed/dotted line in ArcGIS 9. Creating and Orienting Vector Grids in QGIS 2. In this image the red lines are our postcodes, and the yellow area is the highlighted Glasgow City polygon. Little did I know at the time how relevant to my family this would prove. But before we are discussing about drawing contour lines in QGIS, let's start talking a little bit about the concept of contour line, what contour line definition is, contour lines characteristics and and how the method in drawing contour line. There are some layers that can't be represented with a simple line. Open the Layer Properties dialog to start. It is possible to create such a map in QGIS with a simple trick - using custom projections and densification of lines. QGIS Tutorial 05 - How To Create Line Layers, and QGIS Tutorial 04 - How To work with multiple layer QGIS tutorial 03 - How To Split and Merge Polygons QGIS Tutorial 02 - How To Create Polygon Layer and QGIS tutorial 01 - How To Create Layer and Add poi Download and setup Latest version of QGIS Desktop January (2). A new layer called Hub distance should now display lines to hubs, indicating the nearest bus stops to each polygon in the opt_1 layer. So far this is my third tutorial on QGIS. Here's a screenshot for a single layer. polygon so that both polygons overlap and QGIS then clips the second polygon to the common boundary. 4 is a relatively simple and straight forward process. It will open a new conversion window. Each time you click, a new node is added to your polygon. QGIS supports several geometry types such as polygon, point, multipoint, and line. This is the default. Creating a Subset Shapefile from an Existing Shapefile This tip sheet covers how to create a smaller subset data set from a larger data set in ArcGIS. It runs on Linux, Unix, Mac OSX, Windows and Android and can be downloaded free of charge from qgis. They are useful when constraints of space force a label to be moved away from the feature. 1), activate the layer in the legend and click on the Labeling icon which appears in the QGIS toolbar menu. top If you open the Attribute Table of the Hub distance layer, you will see the HubName and the HubDist attributes, the HubName being the bus stop number from the BusStop layer. 8 extends this functionality by allowing addition of more than one vertex using the “+” button. If you’re not familiar with buffered gradients, a great example is the subtle shading. For polygons, the first coordinate pair (point) on the first line segment is the same as the last coordinate pair on the last line segment. Coming in QGIS 3. Number of features to create [number ] Number of offset copies to generate for each feature. montgodb is there any way to force QGIS to use a certain geometry type when displaying a query layer? I'm querying a point layer to derive aggregate point layer and qgis is shows it as a polygon layer and not rendering any of the points. Polygons can be created from a file that contains the points (Longitude and Latitude) that make up the vertexes of each polygon boundary, and the order in which to draw them. 0, we added the ability to extend an existing line feature by clicking a "+" indicator at the start or end of line features when using the node tool. While this was a nice feature, it was missing the much-requested ability to create so-called “buffered” gradient fills. Gordon Luckett shows how to get QGIS up and running on your computer and create maps with vector and raster data. Press Browse button. explose blocks and export lines as SDF, and connect SDF via FDO. In QGIS, the data need to be the data same type (i. Here's a screenshot for a single layer. In figure 1 can be seen the illustration of these topology errors. It does contours too, which have no fill, and so you must use vector > geometry > lines to polygons in order to fill them up. The callout helps to reconnect the label to the feature it refers to. Digitizing Line and Polygon Features with Snapping Next we'll digitize lines and then polygon features, but first we should set the snapping environment. Default: 10. You can say that this is being overrated, but check the differences in the following images. Right-click on the folder and select New > Shapefile. If you wish to map certain points of interest, routes, or polygons but cannot find a shapefile, you can create your own. Set the following:. The data I am using is a … Continue reading Creating Animated Flight Lines in QGIS. Little did I know at the time how relevant to my family this would prove. I will outline the steps to create such a map. We will be doing the same thing in this lesson, albeit at a more advanced level, using QGIS software. A New Polygon dialog box appears, and your cursor changes to. We are almost done with our work on QGIS. It runs on Linux, Unix, Mac OSX, Windows and Android and can be downloaded free of charge from qgis. However this is easier said than done. Cutting lines with a polygon boundary. Or convert geometry type to polyline and offset (assuming it's regular polygon). First you need to have the points, lines or area delimited by a polygon in Google Earth, and save it in kml or kmz format. Create squares and rectangles; Line. By their nature the contours are polyline features, but many GIS users want to represent the area closed between two adjacent contours with a polygon. When you add a new attribute, the attribute value for all existing features are set to NULL for that field index. Calculate the length of a path, its mid-point, and bounding box. For example, you can use census_wake_2000_points loaded into SpatiaLite with the geometry field called geom. Labels with callout lines in QGIS. I assumed that each seat had an equal number of voters. Transform polygon into line and vice-versa using copy/paste. Digitizing Line and Polygon Features with Snapping Next we'll digitize lines and then polygon features, but first we should set the snapping environment. The points correspond to the pixel centroids that intersect the polygon layer. The first step is creating the polygon *. QGIS supports both raster and vector layers; vector data is stored as either point, line, or polygon features. The Create Buffers tool creates polygon buffers around points, lines and polygons. I thought I should write on some basics tools that you might need on your daily task. Save it on a new location. Measure polygon area on Google map. Using QGIS' Reshape Features command to edit polygons I found the Reshape Features command in QGIS useful to manipulate the shape of polygons. line polygon. Performed by the GEOS module. A new release of qProf, plugin for QGis, allows to determine the intersections of line and polygon layers, representing for instance faults and geological outcrops, on a vertical cross-section. This one operation is the atomic building block of many, many different types of spatial queries. line vs polygon) Feature request #6188 : Let the user fine tune stretching values in raster properties/style. …A contour line is a polyline that's usually based…on elevation along a particular path. Thanks for showing how to create a polygon in QGIS and also how to clip a grid with the polygon in SAGA. Notice that in QGIS you can set transparency at color level everywhere (or almost everywhere) there is a color to select. Zoom into the creek at the south-western edge of the code polygon. This data is available as 500x500meter polygons. The counties we displayed on the map are technically polygons, but let’s try loading a different data type. It is however very tightly integrated into QGIS and we do not have to leave the program so I feel this counts as a QGIS solution. …First we need to add the DEMs to the map. You can draw orthogonal (right angle) polygon line segments when you press the Ctrl key. (2) To avoid polygon overlaps, when a new polygon is digitised. Generated Arrows can be either straight or curved. Here in this article QGIS 3. Digitizing Line and Polygon Features with Snapping Next we'll digitize lines and then polygon features, but first we should set the snapping environment. …Exploring the edge and fills can help…to add these types of layer to your map…without hiding the layers underneath. This is the default. As a bit of background, QGIS 2. A new and updated version is available at Sampling Raster Data using Points or Polygons (QGIS3) Many scientific and environmental datasets come as gridded rasters. Polygon Outlines in QGIS I had an effect of an outline around the grid in the Glasgow Commercial Property Density heatmap. This book is a collection of simple to advanced techniques that are needed in everyday geospatial work, and shows how to accomplish them with QGIS. These polygons are one of the input files required for running SpeciesGeoCoder, and they must represent the user-defined operational areas used for biogeographical analyses. Today we are going to learn how to convert polyline to polygon on QGIS. If you’re not familiar with buffered gradients, a great example is the subtle shading. Buildings, Parking lots, or Sidewalks) and then export to an ESRI shapefile from there. QGIS plugins web portal. This tutorial explains the steps involved in creating and editing a shapefile. Creating Shapefiles in QGIS This guide explains how to digitise an area by creating a polygon shapefile layer, and then how to calculate area and perimeter of that shapefile. The first step is to exclude certain lines so that we don't end up with too many polygons, just likely we did with the filter function in QGIS earlier. Snapping is performed to all map vertices - points from the Point vector layer and all Line and Polygon members. Instructions provided describe how to symbolize polygon outlines with either a cased line (a line with fill color and a different outline color), or a dashed/dotted line in ArcGIS 9. Other options would be possible, such as the possibility to declare a polygon as an island, thus "cutting" the larger polygon by the smaller polygon. Lastly, we will create a layer (or multiple layers) that includes only the feature types and tags we want to access. - Polygon layers have both lines, the edges of the polygons, and fills, that color the inside of the polygon. As a bit of background, QGIS 2. Or create series of points on polygon, add buffer to them, produce line from intersection of polygons from buffer. The tag breaks the line up into smaller chunks, and the tag extends the line down to the ground. The lines have been split where they were intersected by polygons, and each line feature has been assigned the attributes of both original layers. First, you will need the Quantum GIS (QGIS) software which is free. But we can't use it with the downloaded data. I'm going to play with the mapping capabilitites of D3. Polygons can be created from a file that contains the points (Longitude and Latitude) that make up the vertexes of each polygon boundary, and the order in which to draw them. Merging can be based on one of these two criteria: Length: a segment is merged to its longest neighbor. 0 with the Split Feature command. 27 Differences Between ArcGIS and QGIS – The Most Epic GIS Software Battle in GIS History It’s a head-to-head GIS software showdown with the star-studded lineup in the GIS industry- ArcGIS vs QGIS. Exercise using QGIS. Click on a series of places on the map to form a polygon. Note: This works in the same fashion for drawing Lines, and after you click to place a Marker, ArcMap will automatically create it. In Movement data in GIS #16, I presented a new way to deal with trajectory data using GeoPandas and how to load the trajectory GeoDataframes as a QGIS layer. Special highlights are support for rule based labelling, rule based styling of attribute tables, and advanced geometry checker, support for digitising curve based geometries, better authentication management and much, much more! QGIS 2. holes in larger polygons. Start an edit session and set the target to the polygon shapefile or feature class. Stratified random sampling in QGIS On December 3, 2012 December 3, 2012 By pvanb In GIS , QGIS , research tools In my previous post I described how you can create a random stratified sampling using GRASS GIS. They are useful when constraints of space force a label to be moved away from the feature. To create one open up a new document in any text editor. The title is "Point in Polygon 2: Walking the line" and was published Aug. Polygon creation. This is important as we need to snap the boundary lines to the vertices on the code polygon. Shapefiles often contain large features with a lot of associated data and historically have been used in GIS desktop applications such as ArcMap. Converting points to lines to polygons and back - QGIS Sometimes your data is vector formatted (point, line, or polygon), but it is not the right kind of vector for a particular type of analysis. The MMQGIS plugin has an option to create a hexagon grid (MMQGIS > create > grid lines layer). The Processing algorithm Count points in polygon does the same thing, but we want to do the task without using it. You should read about snapping in Chapter 4 of the textbook before doing this section. 0 still lacks this feature that would be really a big improvement for digitizing. You could create a polygon topology for the different feature types (i. QGIS: Azimuth and Distance Plugin This tutorial walks you through using the QGIS Plugin Azimuth and Distance Plugin to key in US Survey data to generate lines to denote property boundaries. Generated Arrows can be either straight or curved. The fact-checkers, whose work is more and more important for those who prefer facts over lies, police the line between fact and falsehood on a day-to-day basis, and do a great job. Today, my small contribution is to pass along a very good overview that reflects on one of Trump’s favorite overarching falsehoods. Namely: Trump describes an America in which everything was going down the tubes under  Obama, which is why we needed Trump to make America great again. And he claims that this project has come to fruition, with America setting records for prosperity under his leadership and guidance. “Obama bad; Trump good” is pretty much his analysis in all areas and measurement of U.S. activity, especially economically. Even if this were true, it would reflect poorly on Trump’s character, but it has the added problem of being false, a big lie made up of many small ones. Personally, I don’t assume that all economic measurements directly reflect the leadership of whoever occupies the Oval Office, nor am I smart enough to figure out what causes what in the economy. But the idea that presidents get the credit or the blame for the economy during their tenure is a political fact of life. Trump, in his adorable, immodest mendacity, not only claims credit for everything good that happens in the economy, but tells people, literally and specifically, that they have to vote for him even if they hate him, because without his guidance, their 401(k) accounts “will go down the tubes.” That would be offensive even if it were true, but it is utterly false. The stock market has been on a 10-year run of steady gains that began in 2009, the year Barack Obama was inaugurated. But why would anyone care about that? It’s only an unarguable, stubborn fact. Still, speaking of facts, there are so many measurements and indicators of how the economy is doing, that those not committed to an honest investigation can find evidence for whatever they want to believe. Trump and his most committed followers want to believe that everything was terrible under Barack Obama and great under Trump. That’s baloney. Anyone who believes that believes something false. And a series of charts and graphs published Monday in the Washington Post and explained by Economics Correspondent Heather Long provides the data that tells the tale. The details are complicated. Click through to the link above and you’ll learn much. But the overview is pretty simply this: The U.S. economy had a major meltdown in the last year of the George W. Bush presidency. Again, I’m not smart enough to know how much of this was Bush’s “fault.” But he had been in office for six years when the trouble started. So, if it’s ever reasonable to hold a president accountable for the performance of the economy, the timeline is bad for Bush. GDP growth went negative. Job growth fell sharply and then went negative. Median household income shrank. The Dow Jones Industrial Average dropped by more than 5,000 points! U.S. manufacturing output plunged, as did average home values, as did average hourly wages, as did measures of consumer confidence and most other indicators of economic health. (Backup for that is contained in the Post piece I linked to above.) Barack Obama inherited that mess of falling numbers, which continued during his first year in office, 2009, as he put in place policies designed to turn it around. By 2010, Obama’s second year, pretty much all of the negative numbers had turned positive. By the time Obama was up for reelection in 2012, all of them were headed in the right direction, which is certainly among the reasons voters gave him a second term by a solid (not landslide) margin. Basically, all of those good numbers continued throughout the second Obama term. The U.S. GDP, probably the single best measure of how the economy is doing, grew by 2.9 percent in 2015, which was Obama’s seventh year in office and was the best GDP growth number since before the crash of the late Bush years. GDP growth slowed to 1.6 percent in 2016, which may have been among the indicators that supported Trump’s campaign-year argument that everything was going to hell and only he could fix it. During the first year of Trump, GDP growth grew to 2.4 percent, which is decent but not great and anyway, a reasonable person would acknowledge that — to the degree that economic performance is to the credit or blame of the president — the performance in the first year of a new president is a mixture of the old and new policies. In Trump’s second year, 2018, the GDP grew 2.9 percent, equaling Obama’s best year, and so far in 2019, the growth rate has fallen to 2.1 percent, a mediocre number and a decline for which Trump presumably accepts no responsibility and blames either Nancy Pelosi, Ilhan Omar or, if he can swing it, Barack Obama. I suppose it’s natural for a president to want to take credit for everything good that happens on his (or someday her) watch, but not the blame for anything bad. Trump is more blatant about this than most. If we judge by his bad but remarkably steady approval ratings (today, according to the average maintained by 538.com, it’s 41.9 approval/ 53.7 disapproval) the pretty-good economy is not winning him new supporters, nor is his constant exaggeration of his accomplishments costing him many old ones). I already offered it above, but the full Washington Post workup of these numbers, and commentary/explanation by economics correspondent Heather Long, are here. On a related matter, if you care about what used to be called fiscal conservatism, which is the belief that federal debt and deficit matter, here’s a New York Times analysis, based on Congressional Budget Office data, suggesting that the annual budget deficit (that’s the amount the government borrows every year reflecting that amount by which federal spending exceeds revenues) which fell steadily during the Obama years, from a peak of $1.4 trillion at the beginning of the Obama administration, to $585 billion in 2016 (Obama’s last year in office), will be back up to $960 billion this fiscal year, and back over $1 trillion in 2020. (Here’s the New York Times piece detailing those numbers.) Trump is currently floating various tax cuts for the rich and the poor that will presumably worsen those projections, if passed. As the Times piece reported: