New answers tagged point
Here's a fairly bare-bones python script that connects all combinations of two input point files, and outputs lines with distance attribute. It follows directly from PolyGeo's comment under OP. Note: I've heard horror stories of nesting cursors, but it seems to work in this case. # import arcpy import arcpy, os # set input/output parameters points1 = ...
Do you have access to the Spatial Analyst extension? ArcToolbox > Spatial Analyst Tools > Neighborhood > Focal Statistics
A DEM (digital elevation model) is a raster and not contour lines or polylines. If the point data is a systematic grid of points (equal spacing) then it is as simple as converting straight to raster using a rasterize tool. In QGIS you can use "Raster > Conversion > Rasterize (Vector to raster)". However, if the points are irregular then the becomes a ...
You can use the NNJoin plugin to calculate the distance between points and its nearest line. You can download the plugin via Plugins > Manage and Install Plugins.... It is recommended, however, to not use this plugin on large datasets containing lines as it does not use a spatial index for lines.
You need to do this in a two-stage process using the Vector->Analysis Tools->Mean Coordinates tool in the second step. This tool will return the mean coordinates for sets of point within a layer if they have a unique ID field. So, if you have a polygon layer which defines your areas, do a spatial join (Vector->Data Management->Join attributes ...
if you compute the statistics of your raster, (or with zonal statistics if you look for a specific zone), you can find its maximum value (properties > source > Statistics > max) Then you can use the value in raster calculator Con("raster" == maxvalue, 1) EDIt: where maxvalue is either the raster created by zonal statistics or the value that you read in ...
I realize this is a relatively old question, but as a consulting arborist I have gained much experience with tree surveys and creating graphical representations of driplines and root protection zones, using QGIS specifically. That said, I have to second CHenderson's approach, as it is the one I use for every inventory I conduct. I will qualify that ...
Other way to measure this, it is using Qchainage (QGis plugin) to produce nodes equallly spaced from line. Then, you may use Distance to nearest hub (QGis plugin) to calculate distance among points.
A search with Google threw up these pages... http://blogs.esri.com/esri/arcgis/2011/09/06/creating-radial-flow-maps-with-arcgis/ http://blogs.esri.com/esri/apl/2012/09/12/generating-distributive-flow-maps-with-arcgis/ Someone has even created a tool that flows around country boundaries. ...
The GRASS v.distance function should do the job, but it does not work through QGIS Processing. It can, however, be used through the QGIS GRASS plugin. Other easily available alternatives in QGIS are Distance matrix (under Vector-> Analysis Tools) and the NNJoin plugin.
You could try this in two different ways, either rotating your symbology (mark each location with a symbol that points at ), or rotating a label (each location has a static point symbol, and label rotated). Here's the Esri help page for each method: Rotate the label: Setting label rotation using a numeric field. I think this would work better for your ...
I found the answers provided here very helpful and came up with a refined version. So, here's another way to accomplish this task, but without having to alter the original table. SELECT t1.gid AS gid_1, t2.gid AS gid_2, ST_Distance(t1.geom, t2.geom) AS mindist FROM table t1, table t2 WHERE t1.gid != t2.gid AND ST_Distance(t1.geom, t2.geom) != 0 ORDER BY ...
A wiki article Centroid describes a few methods, including this one, which is probably the one used by most GIS tools: Centroid of polygon The centroid of a non-self-intersecting closed polygon, defined by n vertices (x0,y0), (x1,y1), ..., (xn−1,yn−1), is the point (Cx, Cy), where and where A is the polygon's signed area, ...
Top 50 recent answers are included