[Mobilitydb-users] selected-link-analysis

[SCHOEMANS Maxime]

Hi Jan,

On 30/09/2024 12:28, Jan Willem van der Lichte via Mobilitydb-users wrote:
 > Just wondering, is there something like a selected-link-analysis in 
the mobilitydb environment?
 > Or suggestions what the best approach is to so.

There is no specific function for selected-link-analysis, but you can 
combine multiple existing functions to achieve this.

 > What is the origin from the people passing point X, and what is their 
destination? And that for both directions?

Assuming your point X is a singular geometry and you have a table 
'trips(id, trip, ...)', you can use a query such as:

SELECT id, startValue(trip), endValue(trip)
FROM trips
WHERE eintersects(trip, geometry 'POINT(...)');

This will return the id, start and end position of every trip that 
passes through ('ever intersects') the specified point.
However, I'm not sure what you mean by 'both directions'.

Note that 'eintersects' ('ever intersects') will only return True if the 
trip passes exactly through the specified geometry.
If your geometry is a point of interest near the road, you can use the 
'edwithin' ('ever distance within') function instead.

Based on your specific needs, the query will probably need some 
tweaking, but I hope this already helps.
Let us know if you have any additional questions regarding this.

Best regards,
Maxime Schoemans