Joining CSV tables by multiple attributes
Geographic Information SystemsHow do I combine attribute tables? Joining attributes in one table to another In the table of contents, right-click the layer or table you want to join, point to Joins and Relates, then click Join. Click the What do you want to join to this layer? Click the field on which the join will be
Calculating distance between a point and the nearest line, PostGIS
Geographic Information SystemsHow do you calculate the distance between a point and a line? Quote from video: Minus x1 squared plus y2 minus y1 the quantity squared and you take the square root of that. How do I find the distance between two points in Postgis? You can use ST_DistanceSpheroid to calculate the distance between two geometric
How to create a polygon with a circular hole in openlayers 3?
Geographic Information SystemsHow do you create a polygon with a hole in it Arcgis pro? A hole in a polygon feature is a part of a multipart feature. To create a hole, finish the primary part and sketch the hole. Alternatively, you can split the feature and delete the part, or clip a hole using an existing
How to copy entire fields into a python list
Geographic Information SystemsHow do I copy all the elements in a list Python? Different Ways to copy list: Using the slicing technique. Using the extend() method. List copy using =(assignment operator) Using the method of Shallow Copy. Using list comprehension. Using the append() method. Using the copy() method. What is copy () in Python list? Python
What’s a good way to implement an ‘Attributes to keep’ option in a QGIS processing script?
Geographic Information SystemsHow to write a script for QGIS? Within QGIS, you can use Create new script in the Scripts menu at the top of the Processing Toolbox to open the Processing Script Editor where you can write your code. To simplify the task, you can start with a script template by using Create new script from
Labelling point elevations of raster (DEM) using QGIS
Geographic Information SystemsHow to get elevation data from DEM in QGIS? Method Ensure that DEM and 2d_zsh line layer files are opened, and the Point Sampling Tool plugin has been installed (Plugins >> Manage and Install Plugins >> Point Sampling Tool) Convert line vertices to points, using the preferred method described in the QGIS Convert Lines to
Combine multiple geojsons
Geographic Information SystemsHow do I combine multiple GeoJSON files into one? geojson-merge (for dummies) Start the node. Open cmd.exe. Browse to a folder where you’d like geojson-merge installed. In cmd.exe type the install string from above. Wait patiently, it could take a moment to start. Use cd node_modules to change directory to the node_modules folder. For simplicity
Georeferencing orthorectified raster
Geographic Information SystemsWhat is the difference between orthorectified and georeferenced? Georectify take an image that has not been adjusted to be in a known coordinate system, and put it into a known coordinate system. Orthorectify take an image in its original geometry and very accurately adjust it so that it is in a known coordinate system, with
Joining each grid cells with many records in QGIS
Geographic Information SystemsHow do I join data in Qgis? Joining Data Open the layer properties (double-click the layer) and click on the Joins tab in the left column. Click the green Addition symbol at the bottom of the dialog box. Change the Join layer to the standalone table and change the join and target fields to the
ST_Contains for 3D geometry
Geographic Information SystemsWhat is the difference between ST_Contains and ST_Within in PostGIS? ST_Within(geometry A , geometry B) returns TRUE if the first geometry is completely within the second geometry. ST_Within tests for the exact opposite result of ST_Contains. ST_Contains(geometry A, geometry B) returns TRUE if the second geometry is completely contained by the first geometry. What is