MATLAB: Why doesn’t any data show up on the figure

for looploopplotplotting

i'm trying to make a basic 4-bar linkage position tracking graph, but the graph shows up blank when i run it. any help?
%  Lengths of Linkages
a=269.755;
b=182.014;
c=345.91;
d=154.91;
e=110.524;
%  Initial Angles
theta0=0.544892;
theta20=2.504722;
theta30=0.612262;
alpha=0.559028959;
%  J-Values & Geometry Calculations
j1=d/a;
j2=d/c;
j3=(a^2 - b^2 + c^2 + d^2)/(2*a*c);
j4=d/b;
j5=(c^2 - d^2 - a^2 - b^2)/(2*a*b);
q=atan((a*sin(theta20))/(d-(a*cos(theta20))));
f=sqrt(a^2 +d^2 - 2*a*d*cos(theta20));
p=atan((sqrt(4*b^2*f^2 - (b^2 + f^2 - c^2)^2))/(b^2 +f^2 - c^2));
%  Coupler Position
xc=a*cos(theta20) + e*cos(p-q+alpha);
yc=a*sin(theta20) + e*sin(p-q+alpha);
z=-xc*cos(theta0) - yc*sin(theta0);
%  Range Of Input Angles
theta2=[(theta20-(degtorad(45))):pi/180:(theta20+(degtorad(45)))];
%  Loop
for i=theta2;
D=j5-j1+((1+j4)*cos(i));
E=-2*sin(i);
F=j5+j1-((1-j4)*cos(i));
theta3=2*atan((-E-sqrt(E^2 - 4*D*F))/(2*D));
camber=radtodeg(theta3-theta30);
q1=atan((a*sin(i))/(d-(a*cos(i))));
f1=sqrt(a^2 +d^2 - 2*a*d*cos(i));
p1=atan((sqrt(4*b^2*f1^2 - (b^2 + f1^2 - c^2)^2))/(b^2 +f1^2 - c^2));
xc1=a*cos(i) + e*cos(p-q+alpha);
yc1=a*sin(i) + e*sin(p-q+alpha);
z1=-xc1*cos(theta0) - yc1*sin(theta0);
height=z1-z;
end
%  Plot Results
figure
grid on
xlabel('camber angle(degrees)','FontSize',18)
ylabel('Wheel Travel(mm)','FontSize',18)
title('Camber Angle With Wheel Travel','FontSize',20)
plot(camber,height)
i'm pretty new to matlab so any help would be much appreciated. Cheers Michael

Best Answer

You overwrite camber and height each time through the "for i" loop.
camber = []; height = [];
for i = theta2
  ...
  camber(end+1) = radtodeg(....)
  [...]
  height(end+1) = z1-z;
end
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