Why do not run this code ?

I found this code for teaching about robot arms simulation,but when I try to run in the .m editor and start,...there are some error, Please help me to run the code .Thank you

 figure;
  h = plot3(0,0,0);p = get(h,'Parent');xlim(p,'manual');
  xlim(p,[0 2]);ylim(p,'manual');ylim(p,[0 2]);zlim(p,'manual');
  zlim(p,[0 2]);axis vis3d;grid on;
  point1.x =0;point1.y = 0;point1.z = 0;
  point2.x = 0;point2.y = 0;point2.z = 1;
  point3.x = 0;point3.y = 0;point3.z = 1;
  point4.x = 2;point4.y = 0;point4.z = 1;
  l= line([point1.x, point2.x],[point1.y,point2.y],[point1.z,point2.z],'Color','r','LineWidth',4);
  l1 = line([point2.x, point3.x],[point2.y,point3.y],[point2.z,point3.z],'Color','b','LineWidth',4);
  l2 = line([point3.x, point4.x],[point3.y,point4.y],[point3.z,point4.z],'Color','g','LineWidth',4);
  pause(0.5);
  theta2 = 30;
  theta3 =0;
  for theta1 =70:-1:0
      [point2,point3,point4] = fromDHandTheta(theta1,theta1,theta1); %(each individual theta)
     set(l,'ZData',[point1.z,point2.z],'YData',[point1.y,point2.y],'XData',[point1.x,point2.x]);
     set(l1,'ZData',[point2.z,point3.z],'YData',[point2.y,point3.y],'XData',[point2.x,point3.x]);
     set(l2,'ZData',[point3.z,point4.z],'YData',[point3.y,point4.y],'XData',[point3.x,point4.x]);
     hold on;
     plot3(point4.x,point4.y,point4.z,'xk');
     pause(0.1);
  end
  end
function [point2,point3,point4] = fromDHandTheta(theta1,theta2,theta3)
% D-H Params:
%  N  Theta  Alpha   dN  rN
%  1  theta1 alpha1   0   0
%  2  theta2 alpha2   1   0
%  3  theta3 alpha3   1   0
s1 = [0;0;0]; % from dN and rN
s2 = [1;0;0];
s3 = [1;0;0];
alpha1 = 90;
alpha2 = 0;
alpha3 = 0;
pointa = returnUfromTheta(theta1)*returnVfromAlpha(alpha1)*s1 + [0;0;1]; % [0;0;1] is orig position
pointb = returnUfromTheta(theta1)*returnVfromAlpha(alpha1)*returnUfromTheta(theta2)*returnVfromAlpha(alpha2)*s2 + pointa;
pointc = returnUfromTheta(theta1)*returnVfromAlpha(alpha1)*returnUfromTheta(theta2)*returnVfromAlpha(alpha2)*...
         returnUfromTheta(theta3)*returnVfromAlpha(alpha3)*s3 + pointb;
point2.x = pointa(1); point2.y = pointa(2); point2.z = pointa(3);
point3.x = pointb(1); point3.y = pointb(2); point3.z = pointb(3);
point4.x = pointc(1); point4.y = pointc(2); point4.z = pointc(3);
end
function U = returnUfromTheta(theta)
U = [ cosd(theta), -sind(theta), 0;...
     sind(theta),  cosd(theta),  0 ;...
           0,        0,  1];
end  
function V = returnVfromAlpha(alpha)
V = [ 1, 0 ,0;...
      0, cosd(alpha), -sind(alpha);...
      0, sind(alpha),  cosd(alpha)];
end

Answer 1

[Walter Roberson]

Insert as the very first line,

function armsim

and save the whole thing to armsim.m

You should be able to run it then.

[x y]

Thank you for (quick)Help :)