# Every time I run this code, I get "Error using plot Vectors must be the same length. Error in ex (line 22)

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Omar Ahmad AL Bloushi on 21 Nov 2021
Answered: Kumar Pallav on 24 Nov 2021
%prameters
L = 160
w = 1000 * 2 * pi/60
r = 60
N = 100
th0 = 0
thl = 180
dth = (thl - th0)/N
q=r/L
%calculation
for i = 0:1:N;
th = (th0 + i * dth) * pi/180;
phi = asin (q * sin(th));
dphidt = w * q * cos(th)/sqrt(1 - (q * sin(th))^2);
vd (i + l) = w * r * sin(phi + th)/cos(phi);
wbd(i + l) = -w * r * cos(th)/(L * cos(phi));
ad(i + l)= w * r * ((cos(phi) * cos(phi + th) * (w + dphidt) - sin(phi) * sin(phi + th) * dphidt)/cos(phi)^2);
albd (i + l) = -w * q * ((-cos(phi) * sin(th) * w + sin(phi) * cos(th) *dphidt)/cos(phi)^2);
end
figure
plot ((th0:dth:thl) , wbd , (th0:dth:thl) , albd/100 ,'lineWidth', 2);
xlabel ('\theta ({\circ})') ;
axis ([th0 thl - inf inf]);
figure
plot ( [th0:dth:thl] , vd/10 , [th0:dth:thl] , ad/1000 , 'LineWidth' , 2 );
xlabel ('\theta ({\circ})');
legend ('v_D (10^1 in/s)','a_D (10^3 in/s^2)');
axis ([tho thl - inf inf]);
N = 100
thl = 180
N = 100
clc
KSSV on 21 Nov 2021
Undefined function or variable l...

Kumar Pallav on 24 Nov 2021
Hi,
I assume the variable "L" defined in parameters has to be used instead of "l" inside the for loop.
The error you are getting at this line:
plot ((th0:dth:thl) , wbd , (th0:dth:thl) , albd/100 ,'lineWidth', 2);
Now, the error you are getting is because the plot takes two vectors:
a. (th0:dth:thl) of dimension 1*101 double
b. wbd of dimension 1*260 double
You must have same size of vectors to plot. Refer this for more on plot function.
Hope this helps!

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