Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [de-9im]

The Dimensionally Extended nine-Intersection Model (DE-9IM) is a topological model and a standard used to describe the spatial relations of two spatial objects.

1
vote
1answer
49 views

Role of boundaries when using shapely within function

According to the shapely documentation: object.within(other) Returns True if the object’s boundary and interior intersect only with the interior of the other (not its boundary or exterior) ...
3
votes
1answer
457 views

ST_RELATE - Intersect ignore shared boundary

Using postgis I am trying to find polygons that intersect, ignoring polygons that only have a shared boundary (edge). ST_Relate(g1, g2, 'T********') is a standard intersection. ST_Relate(g1, g2, 'TF*...
2
votes
0answers
284 views

postgis st_relate polygon inside another and sharing a boundary

I am trying to select polygons inside an other one WITH a common boundary. It seems that st_relate is the way but I can't find the right matrix, even if I don't see where the fault is in : st_relate(...
3
votes
2answers
2k views

How to determine if a Polygon is inside another Polygon's hole

Given two valid polygons P and Q, what's the cheapest / fastest way to determine: If polygon Q is inside one of polygon P's holes (interior rings), or vice versa. (see illustration below) To the ...
2
votes
1answer
62 views

Boundary of MultiLinestring in DE-9IM

can somebody help me understand (probably giving visual examples) what does this sentence mean which is quoted from the wiki page of nine intersection model: Those points that are in the boundaries ...
3
votes
3answers
160 views

Using DE-9IM patterns in python plugin for QGIS?

I'd like to compare geometries using DE-9IM patterns in my QGIS plugin written in Python. I've tried to instantiate QgsGeos but it seems there's no such module in qgis.core, as reported by the ...
8
votes
1answer
2k views

What is the difference between Spatial predicates “Covers” and “Contains”?

I try to understand the Spatial predicates of the DE-9IM Intersection matrix. I don't get the difference between predicates Covers (respective CoveredBy) and Contains (resp. Within). I try to draw ...
12
votes
2answers
3k views

How does spatial polygon %over% polygon work to when aggregating values in r?

I'm working on an environmental epidemiology project where I have point exposures (~ 2,000 industrial hog operations - IHOs). These IHOs spray on nearby fields, but the feces water droplets and smell ...
2
votes
1answer
721 views

Regarding spatial relationships, what is the Dimensionally Extended 9 Intersection Model (DE-9IM)? [duplicate]

In plain English what is the Dimensionally Extended nine-Intersection Model (DE-9IM)? What is the meaning of each row/column in the matrix? How can I use that information to build a relation matrix?...
1
vote
1answer
139 views

Get DE-9IM matrix in spatialite?

Is there a way to get the DE-9IM matrix between two geometries in a Spatialite function, analogous to the st_relate() function in PostGIS? (I find it very helpful to spatially join using intersect() ...
1
vote
1answer
166 views

What topologic relation means “interior-disjoint”?

I am using the JTS Topology Suite, and trying to write an expression that means "shape A and shape B are interior disjoint". I read this documentation page but I don't entirely understand the ...
2
votes
2answers
871 views

SQL Server STRelate equivalent of Oracles SDO_RELATE(…mask=anyinteract)

In Oracle Spatial, we are running checks on a graph. The Check should provide Nodes, which are marked as endnodes (Attribute "EDGEDEGREE" equals 1) but are in fact located somewhere along an edge. We ...
11
votes
2answers
962 views

How do I describe a special relationship between connected edges?

Consider this simple situation where three edges connect at a node: I’d like to write a succinct and clear description of the relationship between A and B in such a way that differentiates it from ...
5
votes
1answer
447 views

Is there a standard st_relation_readable() function for translate DE-9IM strings?

Spatial databases, such as PostGIS, implement the DE-9IM model with function st_relate(), which returns a string with domain of {0,1,2,F}, meaning 0=point, 1=line, 2=area, and F="empty set"... See DE-...