How to create a spatial reference file
Geographic Information SystemsHow do you create a spatial reference? You can create a spatial reference with a set coordinate system, spatial domains, and precision. The spatial domains and precision of the output spatial reference can be further modified using the XY Domain, Z Domain, M Domain, Template XYDomains, and Grow XYDomain By Percentage parameters. How do you
How to make pen style show up correct in QGIS map composer legend?
Geographic Information SystemsHow do I customize my legend in Qgis? Legend items The item order can be changed using the [Up] and [Down] buttons or with ‘drag-and-drop’ functionality. Use the [Add group] button to add a legend group. Use the [plus] and [minus] button to add or remove layers. The [Edit] button is used to edit the
Extracting pixels with value in one raster but NoData in other raster?
Geographic Information SystemsWhat is the NoData value for raster? NoData is stored as a mask that is part of the raster dataset, or using a pixel value in the dataset that is not used as a valid value elsewhere in the dataset. For example, -9999 is a common value for storing NoData. How do I change a
How do I get ArcGIS tiles to display a single layer when multiple layers are available?
Geographic Information SystemsWhat is the difference between vector tile and tile in ArcGIS? Vector tiles are much smaller in size than corresponding raster tiles with rendered symbology. This slightly reduces the cost to store and serve the tiles. Vector tile layers can be projected into various coordinate systems, using desktop applications such as ArcGIS Pro, without distortion
Can you do aggregate functions among nearby geometry in PostGIS?
Geographic Information SystemsCan we use aggregate function in where clause PostgreSQL? Aggregate functions are not allowed because the WHERE clause is used for filtering data before aggregation. What is the difference between geometry and geography in PostGIS? PostGIS gives you a choice of two different ways to store geospatial data: Geometry, where it assumes all of your
Parentheses in attributes
Geographic Information SystemsDoes attribute always end with parenthesis? Attributes will never have parenthesis since they cannot be executed. Classes have parenthesis because when initially called you’re most likely looking to execute the creation of a new object of that class. Do methods have parentheses? Functions and methods require parentheses. You never call functions without parentheses: the parentheses
How to reproject vector data?
Geographic Information SystemsHow do you Reproject a vector layer? Steps for reprojecting a shapefile: Open QGIS 2.0 desktop. From the menu bar choose ‘Layers’ à ‘Add vector layer’. A dialog box opens, browse to the location of the required shapefile and click ‘Open’. A shapefile will be displayed on the workspace and the name of the file
Is there a workaround for 80+ layers in OpenLayers?
Geographic Information SystemsWhat is the maximum zoom level in OpenLayers? The available zoom levels are determined by maxZoom (default: 28), zoomFactor (default: 2) and maxResolution (default is calculated in such a way that the projection’s validity extent fits in a 256×256 pixel tile). Can I use Google Maps with OpenLayers? Unlike Bing Google does not allow its
Significant Mann Kendall Tau
Geographic Information SystemsWhat is the significance of Mann-Kendall test? The Mann-Kendall statistical test for trend is used to assess whether a set of data values is increasing over time or decreasing over time, and whether the trend in either direction is statistically significant. The Mann-Kendall test does NOT assess the magnitude of change. What is the significance
Adding vector shapefile with all elements to QGIS V 3.16 not recognized data source
Geographic Information SystemsHow do I fix invalid data source in QGIS? Go to Layer Menu >> Layer >> Add Layer >> Add Vector Layer In the Data Source Manager window: Click the option Protocol: HTTP(S), cloud, etc. Select encoding type: UTF-8 or System (mine defaulted to UTF-8) Type: You can use either HTTP/HTTPS/FTP, Geojson, or Geojson –