非洲人说什么语言
12 questions
0
votes
0
answers
14
views
Calculate pairwise difference between neighboring pixels
I am trying to process an elevation image in GEE (JavaScript editor) to obtain the slope from the neighbors of a focal pixel to it. I want the slope from one specific pixel (e.g., up) to the focal one,...
0
votes
0
answers
25
views
How do I get a focus pixel function based on a given buffer containing surrounding pixels?
I want to calculate the percentage of built-up pixels surrounding each built-up pixel within a 100 sq.km. I know focal function in R can be of use. But I want to understand the actual algorithm behind ...
0
votes
1
answer
103
views
Outlier's neighbours of a raster analysis in Python/GIS
Starting with point clouds from various drone flights, I created a 0'1x0'1m cell raster with the DEM of Differences (DoD). Next, in order to clean outliers cells, I calculated the 0'1 and 99'9 ...
- 23
6
votes
2
answers
190
views
Identifying direct neighbours connected by network in QGIS
I have a point layer of settlements and a LineString layer of a road network. The settlements have been snapped to the network so they are directly connected by it. Settlements are not always at the ...
- 141
2
votes
0
answers
100
views
QGIS - Get the attributes of the neighbors, if not NULL
I would like to extrapolate information contained in a point layer by searching if the attributes of the neighbor feature are not NULL.
The point layer is called 'centro?d_extrapolation'
I'm using ...
- 999
1
vote
2
answers
144
views
Randomly select non adjacent polygons in vector layer (QGIS) [closed]
I am trying to obtain a random selection of polygons (e.g., 100 polygons out of 400) with the condition that the selected polygons are not adjacent among each other.
Any suggestion on how to achieve ...
- 131
1
vote
1
answer
171
views
poly2nb {spdep} how identify if two cities are neighbours
I'm trying to identify if two cites are neighbours using spdep::poly2nb function, but it returns a list with numbers that i can't understand.
For example,
shp_ce <- rgdal::readOGR(dsn = "...
- 113
2
votes
1
answer
205
views
Polygon neighbors in a shapefile in QGIS using aggregate not working
I'm using QGIS 3.28
I want to find the neighboring polygons for each polygon in my layer, which is formed of polygons.
Having searched for available solutions, I've come up with this:
http://...
- 67
1
vote
1
answer
432
views
How Neighbor Contiguity Algorithm actually works
I want to identify neighbors based on queen or rook contiguities in a programming language that does not have the feature yet. I know that tools like spdep, pysal, geoda, and ArcGIS all implement this,...
- 189
0
votes
1
answer
5k
views
QGIS 3.26.3 DEM Application Natural Neighbour is missing in the menu
I want to create a DEM and contours for a architecture site with QGIS. Half a year ago everything worked perfectly fine. Now natural neighbour is just missing in the toolbox. I got the newest version ...
- 11
1
vote
1
answer
109
views
Nearest neighbour analysis with higher elevation using QGIS
How do I calculate the flow that goes through the rainfall drainage points under a railway?
I have two layers:
DT: Point layer with drainage information: DT_id and elevation.
ACA: Point layer with de ...
- 21
1
vote
1
answer
149
views
MapInfo connect points in one layer to a single point in another layer
I have two layers in MapInfo:
Layer 1: employees - hundreds of points
Layer 2: place of work - one point with site location
I am looking to connect (ie draw a line) for each employee to the single ...
- 339