on January 26, 2023
Unable to open shapefile in ArcMap. “Error: Failed to open the dataset.” Question mark icon and “ml” prefix on file name
Geographic Information SystemsHow do I open a .shapefile file in ArcGIS? You can access a shapefile in ArcGIS Pro using a folder connection in the Catalog pane.Add a shapefile to the map Add a connection to a folder. Browse to the location of the shapefile within the folder connection. Right-click the shapefile and select Add to Current
on January 26, 2023
How to get a collection of georeferencing control points in an ArcMap document?
Geographic Information SystemsHow do I get georeferenced data? In general, there are four steps to georeference your data: Add the raster dataset that you want to align with your projected data. Use the Georeference tab to create control points, to connect your raster to known positions in the map. Review the control points and the errors. How
on January 26, 2023
Difference between MapBox and CartoDB
Geographic Information SystemsWhat is Carto in Mapbox? CARTO and Mapbox can be primarily classified as “Mapping APIs” tools. Some of the features offered by CARTO are: Drag and drop data import allows you to create visualizations in seconds. Make sense of your location data and power your business. Does Mapbox use ESRI? For the base maps, ESRI
on January 25, 2023
Spatialite : spatial index on geometries
Geographic Information SystemsWhat is a spatial index PostGIS? Spatial indexes are used in PostGIS to quickly search for objects in space. Practically, this means very quickly answering questions of the form: “all the things inside this this” or. “all the things near this other thing” What is SpatiaLite used for? SpatiaLite is an open source library intended
on January 25, 2023
OpenLayers only keeps the first drawn feature
Geographic Information SystemsHow do you draw lines in OpenLayers? Select a geometry type from the dropdown above to start drawing. To finish drawing, click the last point. To activate freehand drawing for lines, polygons, and circles, hold the Shift key. To remove the last point of a line or polygon, press “Undo”. How do OpenLayers work? OpenLayers
on January 25, 2023
Creating polygon from one line
Geographic Information SystemsHow do you convert lines to polygons? To Convert Polyline Objects to Polygons Set the PROXYGRAPHICS system variable to 0. On the command line, enter mappolylinetopolygon. Press Enter. If you already had a selection set, the selected closed polylines are converted. If you did not have a selection set, select the polylines to convert. Press
on January 25, 2023
How to get correct format of coordinates for export to geojson from QGIS?
Geographic Information SystemsWhat are coordinates in GeoJSON? The coordinate reference system for all GeoJSON coordinates is a geographic coordinate reference system, using the World Geodetic System 1984 (WGS84) datum, with longitude and latitude units of decimal degrees. How do I get coordinates in QGIS? To start capturing coordinates, click on [Start capture]. You can now click anywhere
on January 25, 2023
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.
on January 25, 2023
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
on January 25, 2023
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