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?
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?
If you want to understand the Dimensionally Extended nine-Intersection Model (DE-9IM) or Clementini Matrice, read Christian Stobl Dimensionally Extended Nine-Intersection Model (DE-9IM)(pdf). You can also read the explications in PostGIS: 4.3.6. Dimensionally Extended 9 Intersection Model (DE-9IM)
The method allows to create spatial filters to find relationships impossible to obtain by traditional methods.
If you want to learn it, use the JTS Topology Suite.
The Clementini resulting matrice:
Shows/means
Typically, you use a pattern to find the result: two lines that intersect on a line would be: '1*1***1**', for example
You can use this method in:
A second [theoretical] example may be that of a GIS analyst trying to locate all wharfs or docks that intersect a lake's boundary on a line and where only one end of the wharf is up on shore. In other words, where a wharf is within, but not completely within a lake, intersecting the boundary of a lake on a line, and where the wharf's endpoints are both completely within and on the boundary of the lake. The analyst may need to use a combination of spatial predicates to isolate the sought after features:
The pattern is 102101FF2
#Identify wharfs partly on a lake's shoreline
SELECT a.lake_id, b.wharf_id
FROM lakes a, wharfs b
WHERE a.geom && b.geom
AND ST_Relate(a.geom, b.geom, '102101FF2');
ArcGIS (Relational functions for ST_Geometry)
The Python modules Shapely (look at Python: module Shapely , geometry, spatial predicates, spatial analysis, Clementini matrices (DE-9IM), shapefiles processing and representation with matplotlib (in French)) and de9im
There are many examples of patterns/Clementini Matrix in Dimensionally Extended Nine-Intersection Model (DE-9IM)(pdf)
"