Getting outline of polygon as GeoJSON?
Geographic Information SystemsWhat is the difference between polygon and Multipolygon? A MULTIPOLYGON is a collection of Polygons. MultiPolygons are useful for gathering a group of Polygons into one geometry. For example, you may want to gather the Polygons denoting a group of properties in a particular municipality.
Minimum enclosing polygons for point clusters
Geographic Information SystemsWhat is MBR in GIS? In computational geometry, the minimum bounding rectangle (MBR), also known as bounding box (BBOX) or envelope, is an expression of the maximum extents of a two-dimensional object (e.g. point, line, polygon) or set of objects within its x-y coordinate system; in other words min(x), max(x), min(y), max(y). How do you
Creating new shapefile using pyshp
Geographic Information SystemsHow do you use PyShp? Using PyShp create a Reader object to access the data from the Ireland_LA Shapefile. Create a Writer object to write data to as a new Shapefile. Set variables for access to the field information of both the original and new Shapefile. We will grab all the field info from the
Calculating area with formula gives zero in the attribute table in QGIS
Geographic Information SystemsHow do I replace null with 0 in QGIS? You can do this directly in the field calculator: Open the field calculator. Check the “Update Existing Field” box. Select the field you want to work on. Enter the following expression in the expression box: if(“fieldname” is null, 0, “fieldname”) , replacing fieldname with the actual
Intersection of points for overlapping polygons
Geographic Information SystemsHow do you fix overlapping polygons? Removing overlaps from existing polygons Select the polygon feature whose border you want to maintain. The other polygon will be clipped back to match it. Click the Editor menu and click Clip. Set the buffer distance to 0 and choose to discard the area that intersects. Click OK. How
Unsupervised classification in Google Earth Engine
Geographic Information SystemsHow do you use unsupervised classification in Google Earth Engine? Unsupervised Classification (clustering) Assemble features with numeric properties in which to find clusters. Instantiate a clusterer. Set its parameters if necessary. Train the clusterer using the training data. Apply the clusterer to an image or feature collection. Label the clusters. Can unsupervised learning be used
Editing multiple layers using QGIS?
Geographic Information SystemsHow do I edit multiple layers in QGIS? Select the layer in the Layers panel and click Layer | Toggle Editing. Alternatively you can right click on a layer in the Layers panel and choose Toggle Editing from the context menu. Multiple layers can be edited at a time. The layer currently being edited is
Visibility of multiple points from one other point?
Geographic Information SystemsWhat is a line-of-sight analysis? Line-of-sight (LOS), also called “viewshed analysis,” can be used to determine what can be seen from a particular location in the landscape. Conversely, the same analysis also determines from where within the surroundings that location can be seen. What is Viewshed analysis used for? A viewshed identifies the cells in
Accessing GeoServer on own domain (Windows OS)
Geographic Information SystemsHow do I connect to Geoserver? In a web browser, navigate to http://localhost:8080/geoserver . Log into GeoServer as described in the Logging In section. Navigate to Data ‣ Workspaces. Workspaces page. Click the Add new workspace button. You will be prompted to enter a workspace Name and Namespace URI. Click the Submit button. How to
Add location search to openlayers map
Geographic Information SystemsCan I use Google Maps with OpenLayers? Unlike Bing Google does not allow its map tiles to be used directly in Openlayers, and you can’t use OpenLayers code in the Google maps API so you would need to rewrite much of it. However, it is possible to use javascript to place an Openlayers map and