How to determine and plot a marker where points intersect?

I have two sets of data points: x,y,z & x2,y2,z2. I want to determine at which points the data points intersect and at those points I want to plot a marker. I tried creating two matrices of the two data sets but then I was not sure how to determine from there which rows are equal in the two matrices. My code is below...

clc;
clear variables;
close all;

n = input('number of revolutions '); 
r = input('radius ');
%l = input('length ');
a = input('angle with respect to the upwards horizontal in degrees '); 
w = input('number of wires '); 

h=(2*n*pi*r)/tand(90-a); %height of stent determined by other inputs
%n = (l*tand(90-a))/(2*pi*r); %number of turns
%a=90-(atand((2*n*pi*r)/l));

if mod(w,2) ==0 %number of wires is even
else
    fprintf('ERROR:number of wires must be even'); %stops code if wire number is odd
  return
end

if mod(n,1) ==0 %number of revolutions is whole number
else
    fprintf('ERROR:number of revolutions must be whole number'); 
  return
end

e = (2*pi)/(w/2); %theta (spacing between where each wire starts)

for i=1:w/2
    t{i} = (i-1)*e:pi/w:(n*2*pi)+e*(i-1); %t value for CCW helices 
    x{i} = r*sin(t{i});
    y{i} = r*cos(t{i});
    z{i} = (h/(n*2*pi))*t{1};
    plot3(x{i},y{i},z{i}, '.','MarkerSize',25,'MarkerFaceColor','yellow','MarkerEdgeColor','yellow') %plot CCW helices
   hold on;
end
hold on;

for i=1:w/2 
  t2{i} = (n*2*pi)+(e*(i-1)):-pi/w:(i-1)*e; %t value for CW helices 
  x2{i} = r*sin(t2{i});
  y2{i} = r*cos(t2{i});
  z2{i} =(h/(n*2*pi))*t{1}; 
  plot3(x2{i},y2{i},z2{i},'.','MarkerSize',25,'MarkerFaceColor','black','MarkerEdgeColor','black') %plot CW helices 
  hold on;
end

hold on;

L=cell2mat([x y z])' ;
K=cell2mat([x2 y2 z2])';