finding intersection of two lines?
1 view (last 30 days)
Show older comments
Zeinab Ahmadi93
on 26 Jul 2017
Answered: Roger Stafford
on 26 Jul 2017
Hello
I have two points B(x1,y1) , C(x2,y2), then I calculate the corrdinate of two more points J(xdd,ydd) and k(xgg,ygg) know I want to find the coordinate of yellow star point which is the intersection of line JK and BC, How can I do it? Thanks in advance.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/166338/image.png)
xdd= x1(index1)+(DeltaX*D_CL)/D +(DeltaY/D)*sqrt(r^2-D_CL^2);
ydd= y1(index1)+(DeltaY*D_CL)/D-(DeltaX/D)*sqrt(r^2-D_CL^2);
xgg= x1(index1)+(DeltaX*D_CL)/D-(DeltaY/D)*sqrt(r^2-D_CL^2);
ygg=y1(index1)+(DeltaY*D_CL)/D+(DeltaX/D)*sqrt(r^2-D_CL^2);
0 Comments
Accepted Answer
Roger Stafford
on 26 Jul 2017
If your “yellow star point” is as indicated in your diagram, there is a simple formula for finding it which doesn’t require finding J and K. Define vectors B = [x1;y1], C = [x2;y2], and define rB and rC as the respective radii of the circles with centers at B and C.
BC = B-C;
S = (B+C)/2 - (rB^2-rC^2)/(2*dot(BC,BC))*BC; % <-- yellow star point
Of course, if rB and rC are equal, then S is simply
S = (B+C)/2
which would be the midpoint between B and C.
0 Comments
More Answers (1)
KSSV
on 26 Jul 2017
See this file exchange, so far this is the best one I found: https://in.mathworks.com/matlabcentral/fileexchange/22441-curve-intersections?focused=5165138&tab=function
0 Comments
See Also
Categories
Find more on Lighting, Transparency, and Shading in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!