Curve Intersect 2

Finds the intersection points between two arbitrary polygons.

Description

General

This file is based on the Curve Intersect function by Duane Hanselman. It extends the scope of the function to handle arbitrary lines / polygons, which may also have vertical segments or segments with non-increasing x-values.

Description
Calculate the intersection points of two 2D-lines / polygons.

Usage
[X,Y]=CURVEINTERSECT(H1,H2) or [X,Y]=CURVEINTERSECT([H1 H2]) or
[X,Y]=CURVEINTERSECT(X1,Y1,X2,Y2) or
 -> (H1,H2) handles to line objects
 -> (Xi,Yi) coordinates of lines
 -> (X,Y) coordinates of intersection

Example
x1=rand(10,1); y1=rand(10,1); x2=rand(10,1); y2=rand(10,1);
[x,y]=curveintersect(x1,y1,x2,y2);
plot(x1,y1,'k',x2,y2,'b',x,y,'ro')

• Acknowledgements: This submission has inspired the following:; Minimum distance between two polygons, Fast and Robust Curve Intersections
• MATLAB release: MATLAB 7.0.1 (R14SP1)

[gok gok]

great command, thank you!
Are you planning to include the case of infinite line intersection?
Example:
x1=[0 1]; y1=[0 0];x2=[0.5 0.5]; y2=[0.1 1];
will "intersect" at [0.5,0]

[xiaoxu wang]

 

[Peter Krug]

Works well for me

[Mat Cop]

very useful

[leila k]

 

[Huy Pham]

Could we use it for a higher dimension?

[Dick Benson]

Overcomes limitations of the D. Hanselman version. THANKS!

[David Shepherd]

I'm using this to quickly find the point at which two EXIT functions intersect, its perfect thanks mate.

[Sathish Athreya]

Yes, Obviously it is very fast to find intersection point between curves

[C. Chaya Boughan]

Wonderful program. Worked for some very sticky intensity plots where the points of intersection had been hard to find. Vielen dank Sebastian !!!!

[Carlos Guerrero Mosquera]

 

[Carlos Guerrero Mosquera]

Excellent job!! Thanks!

[Damir]

It is an excelent job, however I found a bug. The function finds wrong intersection, if one of the curves is almost vertical. Please try this:
x1=[0.1 0.1+1e-17]
y1=[-1 1]
x2=[-1 1]
y2=[-1 1]
[x,y]=curveintersect(x1,y1,x2,y2)
plot(x1,y1,'k',x2,y2,'b:',x,y,'ro')

[Nitin Kumar]

Great job !!

[Yan]

works great! thanks

[Tyler Jandreau]

 

[Andreas Lobinger]

One of our students came up with the usage of curveintersect and afaics it works correctly. However the profiler tells me now, that from 300s program runtime 120s are spend in curveintersect and most of the time in the calls to interp1 in curveintersect_l.

Are they really neccessary?

[Martin Fuchs]

Extremly good code ! Thx sharing it !!!

[Zak]

Worked great for me, though my application was quite simple.

[minoo]

 

[Weylan Yutani]

Forgot to say thanks and congrats!

[KYAW KYAW]

Dear Sir/Madam,

I am looking for the intersection of dynamic waves and base line. SO far, I could manage to get few of the intersection points using ratio (Y data of dynamic wave/ Y data of base line) for whole of samples. Pls advise me how should I continue since I was stuck in here so long.

I used your function but mine is dynamic wave form and base straing line so the X -axis is not constant line. So the array is only (1900x1) for wave form and base line. The Y values of wave form is changing but the base line is seems like constant. Let say, there is 64 intersection points visuality but what i can get is only 47 but some are not accutare positions.

Thanks and best regards
Kyaw