drift along converging lines

[cat3appr]

Hello,

 

I have a plot of 2 navigations , red and blue, of 2 ships that are converging and diverging.  Most of the time they are almost parallel.

Is there a way to calculate the maximum drift along the 2 lines?    Even or also  in QGIS

 

NOTE -  the command must take into account   the drift over a certain range  only,  say on a 100m range, or else , as there are different passages of the lines, 

the command would see also  the far most  drift from lines too far apart...please see the photos

 

many thanks!

Edited March 9, 2020 by cat3appr

[BIGAL]

For a lisp answer its pretty straight forward use the Vl command Getclosestpointto you just walk along one of the plines and check the 90deg distance to the other pline. You use the VL Getpointatdist to walk along say at incremments, if the pline is a collection of points then you can use the Pline vertices. 

 

This has been asked before here thinking what search phrase to use. distance between 2 plines ?

 

(setq ptclose (vlax-curve-getclosestpointto obj2 pt))
(setq dist (distance ptclose pt))

 

Edited March 9, 2020 by BIGAL

[cat3appr]

No I haven't found anything similar, please note, as I explained, it  cannot be something that just keeps into account the distance between 2 lines, please see the screenshots... there are multiple passages of the lines same DWG, look at the first screenshot and you will understand why the lisp you suggested won't work.

thank you  

[BIGAL]

You wanted the distance between 2 plines that's what I offered. With no dwg how are we meant to look further.