Qgis clip polygon

intersection - Vector Intersect QGIS (1

How to clip vector layer using Polygon on QGIS 3

  1. Welcome to QGIS Tutorial. Today, we are going to show you how to clip a vector layer using polygon on QGIS. I am using QGIS version 3.0 on this tutorial. If
  2. Clip layer [vector: polygon] Layer to be used as clipping extent for the input vector layer. Additional creation Options [string] Optional. <put parameter
  3. You can substract (clip) a polygon from another of the same layer by using the plugin Clipper. You have to choose the polygon you want to clip and then you do

If you are digitizing polygons and you want to digitize an interior polygon (lets say put a body of water in a field) you can use the fill ring tool to digitize QGIS How to create a polygon, cut it and merge.Add the advanced editing toolbar in QGIS to see the merge tool www.gis-solutions.co.u Mit dem Plugin Clipper können Sie ein Polygon von einem anderen der gleichen Ebene subtrahieren (ausschneiden) . Sie müssen das zu schneidende Polygon auswählen und This algorithm clips a vector layer using the polygons of an additional polygon layer. Only the parts of the features in the input layer that falls within the

Clip vectors by polygon - QGI

  1. Click the Vector menu at the top of the QGIS program, mouse-over Geoprocessing Tools, and click Clip... There are 3 areas to this tool you will need to be concerned
  2. A QGIS Tutorial showing how to clip vector layer using polygon. To read the tutorial, please visit the following page
  3. QGis - Clip Werkzeug, Maske, Polygon, Koordinaten. Wenn du dir nicht sicher bist, in welchem der anderen Foren du die Frage stellen sollst, dann bist du hier im
  4. You will see the Brazil boundary polygon now loaded in QGIS. Now go to Raster ‣ Extraction ‣ Clipper. Select the input file (raster) as Brazil_mosaic. Name the
  5. Start an edit session from the Editor toolbar. Using the Edit tool, select the overlaying polygon. Click the Editor drop-down arrow and select Clip. Leave the buffer

Consider this example, a single layer includes a Polygon A, a Polygon B1 and a Polygon B2. Polygon A consists of Polygon B1 + Polygon B2 + empty Clip Thiessen Polygons to Original Polygon Boundary. Using the Intersection tool, we can now overlay the thiessen polygons on the original polygon layer to

qgis_clip_video Erase (Difference) Input Layer: Layer, aus dem Daten entfernt werden sollen (z.B. Straßennetzwerk) Overlay Layer: z.B. Polygon-Layer der Region How to clip vector layer using Polygon on QGIS 3 . The Editor > Clip command only clips polygon features that are within a buffer distance of a selected Wenn die Werte für Eingabe-Features oder -Dataset Punkte sind, können die Clip-Features Punkte, Linien oder Polygone sein. Wenn Punkt-Features mit Punkt-Features Once selected, click the polygon for Sri Lanka to select it. Keep the selection as it is and open Processing ‣ Toolbox . Search and locate the GDAL ‣ Raster extraction buffers on qgis (how to make buffer zone around point, line, polygon vector) how to make and use buffers to count structures with qgis. how to buffer point and

QGIS offers multiple raster extraction tools to clip a raster layer by extent or by a polygon feature. The Clip Raster by Extent tool clips a raster to a Clipping and projecting data with QGIS. Extract the dataset to a simple path such as C:\data\PhiladelphiaBaseLayers. Open the folder and explore it a bit. You'll see POLYGONS: source - Polygons. Path to a vector layer. OUTPUT: rasterDestination - Clipped. Path for new raster layer.... further parameters passed to I want to remove the parts of the 'Work Area' polygon that are to the right of the creek line, so that the right edge of the polygon follows the creek line exactly [Qgis-user] Clipping tool takes a lot of time Jonas Sjögren Sun, 12 Oct 2014 14:32:10 -0700 Hi, I am trying to clip a road network by a polygon in a script using

I think I am just enjoying QGIS and writing tutorials on it. So far this is my third tutorial on QGIS. I thought I should write on some basics tools that you might Author Name: KL Higgins (KL Higgins) Original Redmine Issue: 19797 Affected QGIS version: 3.0.1 Redmine category:editing As reported on stackexchange, I have run into

Splitting and clipping shapefiles with QGIS Posted by Unknown. In my last blog post, we improved a dataset containing all municipalities of Norway by merging polygons in QGIS. The municipality polygons include the sea areas, which makes it harder for people to recognize the shapes, as we're used to see Norway with all its fjords and islands. So let's use QGIS to remove the sea from all. I've tried using Raster >> Extraction >> Clip raster by mask layer, but the resulting raster has different values from those of my input raster and isn't even displayed on QGIS. I tried clipping the same raster but with a different polygon file and it worked just fine, so I think the problem might be with the protected areas shapefile. I.

qgis - Cut/Clip/Split a polygon with another polygon from

Polygon A consists of Polygon B1 + Polygon B2 + empty space. I want to clip Polygon A and get the resulting Polygon B1, Polygon B2 and Polygon C, where Polygon C is equal to Polygon A minus (Polygon B1 plus Polygon B2). In other words, the result that I need are the original polygons cookie cutted by all the lines present in the shapefile. (my real dataset has thousands. Polygon: Eine Vektorebene mit nur 1 Polygon. Ich möchte eine neue Ebene mit den darin enthaltenen abgeschnittenen Linien erstellen. Also nur der Teil der Linien innerhalb des Polygons (einfache Clip-Funktion). Ich benutze die Funktion qgis: clip, die ziemlich einfach ist. Zuerst bin ich gescheitert, weil ich nicht wusste, dass diese Clip. Ausschneiden eines Polygon-Features. Sie können mit dem Befehl Ausschneiden jetzt problemlos Polygon-Features ausschneiden, die sich innerhalb des Pufferbereichs eines ausgewählten Features befinden oder an diesen angrenzen. Um ein Polygon-Feature ausschneiden zu können, muss dieses editierbar und sichtbar sein. Nur Polygon-Features werden.

Clipping raster grid with polygon This section describes a few key pre/post processing tools using elevation data from the Top End of the Northern Territory Australia. This data is provided in the native SRTM zip format with the accompany national park boundary file here. Now we can clip the elevation raster grid with the Polygon UPDATED for QGIS 3.4! QGIS Flickr Group. More Photos RSS - Posts. 3,542,048 hits; 8 comments Morten Agerlin said: 2017-08-2922:02. Smart trick - will try that next time I run into the problem. It could be worth also mentioning the Grass algorithm v.clean with bpol as selected cleaning tool in processing. Typical errors are polygon borders intersecting itself - here I often have had to. I think I am just enjoying QGIS and writing tutorials on it. So far this is my third tutorial on QGIS. I thought I should write on some basics tools that you might need on your daily task. 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. If you want me to write specific. Split or Sub Divide polygon layer using QGIS. 7. Now correct attribute table as all the split polygons will have same entries in attribute table. In this way you can split the polygon into multiple polygon entity. If you find any problem in Split Sub Divide polygon - Shapefile, kml, GeoJson data, then do comment below with the problem statement, so that we can look for solution together. Or. After adding the layers you wish to clip, decide which polygon shape you want to clip your data to. The simplest way is to draw a polygon shape and convert it; however, you could use any polygon shapefile for this. 2. Pick the shape you want to draw from the drawing toolbar. (If you do not have a drawing toolbar, go to View - Toolbars - Draw) This example will be using the circle. 3. Draw.

Clipping in ArcGIS and Clipping in QGIS • North River

I'm new to QGIS (long time ARC user) and I'm unable to figure out how to clip a raster to a polygon outline. I've tried a few different polygons and the tool raster>extraction>clip raster by mask layer. However when I run the tool it clips to the extent of the polygon (I. E. A rectangle ) rather than the outline. Sure I'm missing a tick box in settings somewhere! Any help appreciated! 3. It is possible to split a polygon feature by interactively drawing a line over it in QGIS 2.0 with the Split Feature command. The command doesn't seem to be accessible from the menus and only available as a tool bar item in the Advanced Digitizing tool bar palette.The following shows how to access it to split a polygon Clipping a polygon feature. You can clip polygon features that touch or are within a buffered distance of a selected feature using the Clip command. To be clipped, the polygon features must be editable and visible. Only polygon features are clipped. For example, suppose you want to model the effect of a proposed road widening project on the lots of a subdivision block. You can do this using.

Clip Data Merge Shapefiles Geocoding In QGIS, the data need to be the data same type (i.e. all polygons or all points) and in one folder with no other data. Each layer should be the same underlying projection (check the layer properties, since difference won't be visible in the Project's Map Canvas panel). Process Click on the Vector menu, Data Management tools, Merge Shapefiles to One. Qgis Clip Raster Using Polygon In Qgis Extract Raster Youtube . Click on raster conversion polygonize raster to vector. Raster to polygon in qgis. Input vector layer with point line or polygon geometries. Another common operation when working with rasters is to clip a raster to your area of interest. No simplify the edge of the polygons will conform exactly to the input raster s cell edges. Drawing lines, points or polygons (vectors) in QGIS. Input options: Any georeferenced image file or WMS layer containing features you would like to trace. Output options: A shapefile or KML file with vector features. Strengths / weaknesses: QGIS is simple, free, open-source software Open the georeferenced image (Layer > Add Raster Layer) or WMS layer (Layer > Add WMS Layer) in QGIS Donut Polygons in QGIS The process of creating Donut Polygons in QGIS is a two step process: Create the outer ring first. Digitize the inner ring in the end. Inner vs. outer ring of a Donut Polygon Make sure you are in an editing session by pressing the Toggle Editing tool . Then create the exterior ring of your polygon using the Add Feature tool. Once the exterior ring is finished.

Perfect Polygons in QGIS Author: An Introduction to the Polygonize Tool Created Date: 2/27/2016 9:23:15 AM. Here are the steps to merge features of shapefile in QGIS. Merge two or more polygons, points or polyline of Shapefile in QGIS: We can merge two features in Shapefile in QGIS easily. Let's say I have a Shapefile states.shp and I want to merge two states. Open up your QGIS tool. 1.) Select the layer and click the toggle edit button from the toolbar. 2.) Click on select tool from toolbar as.

GIS Solutions - QGIS How to create a polygon, cut it and

Ausschneiden / Ausschneiden / Teilen eines Polygons mit

Class: QgsGeometry¶ class qgis.core. QgsGeometry ¶. Bases: sip.wrapper A geometry is the spatial representation of a feature. QgsGeometry acts as a generic container for geometry objects. QgsGeometry objects are implicitly shared, so making copies of geometries is inexpensive. The geometry container class can also be stored inside a QVariant object Please note that QGIS, when clipping a Point layer, also converts its geometry type to MultiPoint. This geometry type is not suitable for some of the functions we will use in the next step and therefore we will first see how to convert the geometry type back to Point. Fig. 3.4.1 In the information of the places_clip layer we can see that its geometry is MultiPoint. 3.4.1. Convert geometry type. Eine Idee zur Lösung habe ich bei QGIS 3.18 Divide polygon by points [duplicate] gefunden Mit dem Plugin Clipper können Sie ein Polygon von einem anderen der gleichen Ebene subtrahieren (ausschneiden). Sie müssen das zu schneidende Polygon auswählen und dann Vector-> Clipper-> Clip ausführen. Das Plugin subtrahiert das Polygon vom größeren. Dann wählen Sie das abgeschnittene Polygon. Calculating the area of a polygon; Creating a spatial index; Calculating the bearing of a line; Loading data from a spreadsheet; 3. Editing Vector Data . Editing Vector Data; Introduction; Creating a vector layer in memory; Adding a point feature to a vector layer; Adding a line feature to a vector layer; Adding a polygon feature to a vector layer; Adding a set of attributes to a vector layer.

Vektorlayerüberlagerung - QGI

Changelog for QGIS 2.18 Clipping a roads layer with 1 million lines against 2 polygons. Earlier versions: 5 mins 30 seconds. QGIS 2.18: 10 seconds. Clipping a 5 million point address layer against 2 polygons. Earlier versions: 50 minutes. QGIS 2.18: 30 seconds. This feature was funded by North Road. This feature was developed by Nyall Dawson (North Road) Feature: Bounding boxes algorithm. Run the follwing Python script in QGIS Python console to create a memory layer with samples points and the intersection area in map units. You can join this layer on id with the original points. 03:08. 2. ext = layer.extent() for getting the extent of a vector or raster layer. The best results generally come from polygon layers. Today, we are going to show you how to clip a vector layer using polygon on QGIS. Summary. Step 10. 0. fill it with a nodata value using gdalcalc. Create a polygon of the extent you want to cover. Default: 100.0. I want to do an Extract by Mask for each of the. Qgis 2 18 X How To Create A Connection To Mysql Database Mysql Connection Database . Georeference Convert Clip And Merge Rasters Qgis 2 18 Raster Converter Clip . Qgis Export Symbology To Qgis Layer File Qlr Similar To Arcgis Layer File Lyr Symbology Layers Export . Qgis Random Points Inside Polygon Create Single Or Multiple Random Points For.

Video: Clip Data - QGIS Introduction - LibGuides at Duke Universit

qgis - Getting Clip raster ERROR 1: Did not get any

3.4.1 — Shape Tools is a collection of geodesic shapes and tools. Create ellipse, line of bearing, pie wedge, donut, arc wedge, polygon, star, ellipse rose. Clip polygon by raster. Dear QGIS users, I would like to ask how to clip a polygon using a raster layer? basically, I have a raster layer and I want to use it as a clip layer to my vector.. QGIS Documentation Project 2.8 Documentation QGIS 2.8; weiter; zurück | » QGIS Benutzerhandbuch 2.2 » Clip points with polygons ¶ Beschreibung¶ <put algorithm description here> Parameter¶ Points [vector: point] <geben Sie hier die Parameterbeschreibung ein> Polygons [vector: polygon] <geben Sie hier die Parameterbeschreibung ein> Add Attribute to Clipped Points [tablefield: any. Clip; Difference; Dissolve; These are all located under the Vector menu. Create Polygon Centroids¶ Add the parcels layer to your project. Under Vector select Geometry Tools and then Polygon Centroids. The image below doesn't show the last portion of menu tree. Select the layer to create centroids from, and specify the output data set name. Buffer¶ Buffering the centroids by 1000 feet. This simplified method uses a polygon area to clip the DEM and a single base elevation to base the volume calculations from. This method is best used for estimating volumes where the surface will be left flat, such as filling a lake to the level of a dam or leveling an area of ground. In contrast, the advance method creates an interpolated terrain that the volume is based on. The difference in.

Clip a polygon with another polygon using Global Mapper In GIS data editing work, it may be useful to clip a polygon with another polygon in a simple boolean operation. Global Mapper can perform the clipping task using the Cut Selected Area(s) from another Area (Add Islands) function After opening a new QGIS project, we will start by importing a DEM/DSM raster into the map. This requires creating a new polygon area to clip the DEM raster to. With QGIS create a New Temporary Scratch Layer from the Layer menu bar. Then from Create Layer select New Temporary Scratch Layer. A new window will popup with settings for the temporary layer. Enter in a unique layer name. Features:• Input coverage can be points, lines or polygons• Clip cover is always polygon coverage• The attributes of the resultant coverage is mainlyfrom input and not from analysis coverage.- e.g. Extraction of datasets from various coveragespertaining to an administrative boundary 25. Working withClip Tool 26 GIS tools can be used to create spatial data through line, polygon and point. This article will discuss about the creation of polygon feature using GIS. Open QGIS by clicking on Start then go to All Programs and then click QGIS Desktop 3.8.3. Open the georeferenced toposheet via Layer then click Add Layer followed by Add Raster Layer

How to Clip Vector layer with polygon in QGIS - YouTub

0:00. 0:00 / 51:26. Live. •. Ich muss die ID (oder den Namen) der Eckpunkte einer Polylinie (oder eines Polygons) kennen, um so etwas wie dieses Bild zu erstellen. Als Schritt unten habe ich bereits den Befehl @geometry_point_num verwendet, um die ID des Scheitelpunkts zu haben, aber er gibt nur die Nummer des Scheitelpunkts auf dem. I have two polygons shapefiles and I'd like to clip one by the other. I search on google but I could find only clipping by a bounding box or clipping points by polygons, and that's not what I need... Creating Clipping Polygon and Clipping Interpolation Surface This portion of the tutorial will provide instructions on how to create a clipping mask for the interpolation raster surface. The idea is to digitize a polygon of the lake boundary and then clip the interpolated surfaces with it, so that the interpolation does not extend onto land (which may have very different As concentrations. Clipping is a common operation and GDAL is well suited for it. First, in the QGIS Python Console, run import the processing module: import processing. Next, run the processing command specifying the input image name as the second argument and the output image as the seventh argument: processing.runandload... Subscriber Access In GIS, to clip is to overlay a polygon on one or more target features (layers) and extract from the target feature (or features) only the target feature data that lies within the area outlined by the clip polygon. In other words, the boundaries of the second polygon are imposed on the first polygon. All other area is discarded and is no longer part of the first polygon feature The clipped.

QGis - Clip Werkzeug, Maske, Polygon, Koordinaten - Das

See also the series of video modules in QGIS linked from the Workshop pages or listed below. 1. User Interface, Open Layers, Selection Youtube. 2. Selection Tools Youtube. 3. Projections, Adding CSV, & Heatmap Youtube. 4. Point in Polygon Youtube. 5. Table Join, Spatial Join, and using CSVT Youtube. 6. Distance Matrix and Summary Join Youtube. 7. Buffer, Difference, Clip Youtube. 8. clip Procedure. เมื่อรวมภาพได้แล้ว หากต้องการตัดภาพ สามารถใช้ Polygon ในการตัดได้ดังนี้. ไปที่เมนู Raster —-> Extraction —-> Clip raster by mask laye We can see a red polyline and a yellow polygon with blue outline in QGIS map canvas. To show and hide the drawing object use hide and show method. Type it in the console. polyline. hide() # to hide polygon Polyline. show() # to show polygon. Figure 1. Polyline and Polygon drawing: That's all the tutorial how to add polyline and polygon with python in QGIS. Please see other tutorials which.

Exercise: Clip multiple layers to a polygon. We will take multiple country-level data layers and use the batch processing operation to clip them to a state polygon in a single operation. Open the batch_processing project from the data package. Select the India-States layer and use the Select Features tool to select a state by clicking it. Next, use the Extract selected features processing. gdal_aspect: QGIS algorithm Aspect gdal_assignprojection: QGIS algorithm Assign projection gdal_buffervectors: QGIS algorithm Buffer vectors gdal_buildvirtualraster: QGIS algorithm Build virtual raster gdal_buildvirtualvector: QGIS algorithm Build virtual vector gdal_cliprasterbyextent: QGIS algorithm Clip raster by extent gdal_cliprasterbymasklayer: QGIS algorithm Clip raster by mask laye

How To: Clip a grid to a specific polygon shape Summary. A grid is a raster data storage format native to Esri representing either discrete data (integer grids) or continuous data (floating-point grids). In some cases, a grid with a large extent must be clipped to a specific polygon shape, keeping only the areas within the polygon. There are several methods to clip a grid to a specific polygon. The free QGIS software can be used to easily convert points in shapefile maps to polygons. The resulting polygon map can be loaded directly into StatPlanet to create an interactive point map, such as an interactive map of world cities or US cities.. Converting points to polygons can be done in just three steps: Insert the points layer: In QGIS, insert the shapefile map containing the points.

Digitizing is an essential process of any GIS related project, it is generally part of the data conversion process. This tutorial will take you through the procedures for digitizing scanned map or any other raster dataset in QGIS. By the end of this tutorial, you would have acquired the following GIS basic skills: Creating shapefil Clip out features not within target building polygons; Select features within the target building polygons, includes area sizes; Calculate percentage of rooftop which is south facing; Workflow Screenshots. Process lidar dsm.asc into aspect rasters. Using the QGIS Toolbox: GDAL → Aspect (run in batch for multiple asc files) Source asc file. QGIS Tutorial Videos; QGIS Tutorial Videos 01 - Open and view data From: VisionZ 02 - Projections From: VisionZ 03 - Print composer From: VisionZ 04 - Working with Attributes From: VisionZ 05 - Plugins From: VisionZ 06 - Import data from spreadsheet (LibreOffice and Excel) From: VisionZ 07 - Basic Vector Styling From: VisionZ 08 - Creating custom SVG sysmbols From: VisionZ 09 - Labeling points.

Support for arbitrary geometry clipping and multi-polygon clipping; The Planet QGIS Plugin V2.1 adds a toolbar to your QGIS project with the following panels: Planet Imagery Search Panel (learn more about imagery search capabilities) Planet Basemaps Search Panel (learn more about Basemap search capabilities) Planet Inspector Panel (learn more about the Planet Inspector tool) Planet Tasking. Karl-Anthony Towns Índice Primeros años Trayectoria deportiva Estadísticas de su carrera en la NBA Selección dominicana Referencias Enlaces externos Menú de navegación«Minnesota se queda con Towns»«Towns Jr. going global»«Karl Towns Jr. commits to Kentucky»«El jugador dominicano de instituto Karl Towns Jr. maravilla con un cuádruple-doble»«Karl-Anthony Towns Bio - Kentucky. Sometimes, a project requires customized parcels and land lots. We may choose to draw these in QGIS or in AutoCAD. In QGIS, we can create vector layers of points, lines, or polygons. In this tutorial, we will learn how to draw polygons of building footprints. 1. Create a new vector layer 2. Draw polygons 3. Edit vertices 4. Move polygons 1 Re: [Qgis-user] Clipping WMS Layer for Export to Geo PDF. kirk Sat, 31 Jul 2021 03:02:18 -0700. Hi StewartI assume you are using a rater as a background layer and therefore you will always end up with a rectangle as your final extent. If you clip to an irregular polygon, you will still have a rectangle but the outer area that had been clipped. This can be achieved in QGIS by using the Invert Polygon styling option. For example, below we have a map of the UK with Counties, Schools, Hospitals and ARoads. At the moment the map is a little messy! We have decided that we only want to show/print the map elements that are within the County of Northamptonshire. The first step is to only show the Counties where the Name is Northamptonshire.

Raster Mosaicing and Clipping — QGIS Tutorials and Tip

How To: Clip an overlaying polygon area from an underlying

QGIS: Erweiterungen > OpenlayersPlugin > OpenStreetmapLayer etc. hinzufügen ArcGis: Daten > Daten hinzufügen > Grundkarten hinzufügen Der Bildschirminhalt lässt sich wie bei Thema Google beschrieben, als georeferenziertes Bild speichern Im QGIS sind über OpenLayers neben der Standard OSM-Karte folgende Themen verfügbar OpenCycleMap OCM PublicTransport OCM Landscape. Online-Datenquellen. Water polygons. Polygons for oceans and seas. These polygons are split into smaller overlapping chunks that are easier and faster to work with. Description. The data has been derived from OpenStreetMap ways tagged with natural=coastline. Ways are assembled into polygons and then split. Some errors in the OSM data are repaired in the process PAT - Precision Agriculture Tools Plugin for QGIS ( August 2020 PAT v1.0.0 ) | 5 Table 1 Brief description of tools available in PAT PAT TOOLS DESCRIPTION Create Block Grid Convert polygon features (e.g. a block boundary - see page 57) to • a TIFF raster; and • a VESPER text grid file of X,Y point values used by VESPER QGIS-Tipp: Polygonüberlappungen zählen Veröffentlicht am April 29, 2020 von geoobserver Letzte Woche habe ich auf Twitter ein QGIS-Modell [1], [2] von @kgjenkins gefunden, welches einfach und komfortabel Polygon-Überlappungen zählt Dieses Anfänger-Tutorial für QGIS zeigt mit einem Video und einem bebilderten Text, wie ihr Daten (Punkte, Linien und Polygone) vektorisiert und behandelt

QGIS, clip my vector data with a DEM raster - GeographicVector Spatial Analysis (Buffers)Why don&#39;t the Clip Raster by Mask show proper band valuesqgis - How to divide a shapefile based on a 500x500m gridExtract raster pixel values from shapefile in QGIS3

Find Neighbor Polygons in a Layer¶ There are some use cases where you want to find all neighboring polygons of each of the polygons in a layer. With a little python script, we can accomplish this and much more in QGIS. Here is an example script you can use to find all polygons that share boundary with each of the polygons in a layer and also. QGIS plugins web portal. QGIS plugins add additional functionality to the QGIS application. There is a collection of plugins ready to be used, available to download.These plugins can also be installed directly from the QGIS Plugin Manager within the QGIS application QGIS is supported by donors and sustaining members. A New functionality was introduced which allows users to clip a map item to a shape or polygon item from their layout, allowing for non-rectangular maps within the layout. This feature was developed by Nyall Dawson. Feature: Support for rotated ticks/annotation. Tick marks and annotations on a map frame in the print composer can now be. I am using Clip to sort out all the fire stations that within the boundary of a city, which is a practice from the book, Mastering QGIS(second edition).However, my QGIS 3.6 Noosa goes wrong with the command, as is shown in the following pictures