# Line Intersection Function

Sergey Louks shared this idea 4 years ago
Completed

Could you please add Line intersection function? Yes I know that there is Draw Lines function but it works in a way which isn’t convenient. Using this function for finding line intersection point takes too many steps.

As it works now I have to do the following steps:

Variant 1:

•Set A and B points to create the 1st line

•Set another points C and D to create the 2nd line

•Chose Add track tool and draw the 1st line/route between A and B points

•Remember bearing between A and B points

•Cancel the line/route

•Draw the second line/route between C and D points

•Remember bearing between C and D points

•Cancel the line/route

•Chose Geocaching tools -> Draw Line. Draw the 1st line. Set A point as a starting one and for the 2nd point chose Projection tool (pick location menu), set A as a location point, set bearing between A and B points and then set the distance (e.g. 10km)

• Draw the 2nd line. Set C point as a starting one and for the 2nd point chose Projection tool (pick location menu), set C as a location point, set bearing between C and D points and then set the distance (e.g. 10km)

•Find intersection of two lines (you have to zoom the map very close) and set POI point at the place of intersection.

Variant 2

•Set A and B points to create the 1st line

•Set another points C and D to create the 2nd line

•Chose Add track tool and draw the 1st line/route between A and B points

•Remember bearing between A and B points

•Add the 3rd point. Chose Projection tool (pick location menu), set B as a location point, set the bearing between A and B points and set the distance (e.g. 10km)

•Save the route

•Draw the line/route between C and D points.

•Remember bearing between C and D points

•Add the 3rd point. Chose Projection tool (pick location menu), set D as a location point, set the bearing between C and D points and set the distance (e.g. 10km)

•Find intersection of two lines (you have to zoom the map very close) and set POI point at the place of intersection.

Very often I use Line intersection function for searching objects which are located at a far distance from me. I do this by using terrestrial triangulation (shooting from several different points) and finding object’s bearing. I also use Line intersection function for finding a shooting point (a place from which a photo was taken).

It would be great if this function was working in the following way:

•Using Pick location menu we set 4 points – A and B for the 1st line and C and D for the 2nd.

•Press Compute or the program itself finds intersection point and shows the result as GPS coordinates or creates POI point on the map. If there is a possibility to draw the lines until they intersect it will be excellent.

Now I do it in the following way:

•Find A,B,C,D points in Locus

•Remember coordinates of these points

•Launch GeoCache Calculator, chose Coordinates tool -> Intersection lines and type in A,B,C,D coordinates.

•Find intersection points, launch Locus and type in coordinates of the intersection point.

0

hello Sergey

if you`ll have time, please check this test version http://forum.locusmap.eu/viewtopic.ph... and again function Draw line (now renamed to "Line tools")

there are now two tabs, at first define first line, at second second line. It`s not yet perfectly clear but I`m sure it will work. Only problem remain that computed coordinates are on sphere and not at ellipsoid. I`ll try to improve it till next version

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Wow! Great work! Now it мery precisely locates the intersection point. Is it possible to add opportunity to draw these two lines? This will be useful in the analysis of the accuracy and correctness of points positions.

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I`ve added also definition of second point to same page, so it looks as you may see on screenshot. Lines are also drawn on map. I`m anyway not much satisfied with results. Currently I spend on this feature almost a day, just because I`m unable find working algorithm that compute intersection on ellipsoid. So current system will return quite un-precise values mainly for longer distances, so keep it in mind. Unfortunately ...

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Thanks for such fast response on feature request! You are simplified my life :)

0

sure, you`re welcome

final simplification