Determining wall position through plotted points

Hello,

I'm quite new to MatLab, so please excuse my cluelessness in advance.

For a project, I had to implement pictures in MatLab that display airflows in front of a reflecting wall in form of 2D vectors. These vectors are then transformed into points and now I have to determine where exactly the position of the wall is. I can do this by finding out where there is a "mirroring" of points, because the points right in front of the wall are mirroed in the reflection of the wall. I should be able to put a line through these symmetrical points which represents the wall. So I have to programm in Matlab, that the mirrored points need to be found with a line going through the middle. I just don't know how to program this in MatLab and hope someone has an idea how to do this.