Vectors Must be same length. Do I use Linspace or ?

2021 4 6
1 个回答
回答已采纳
更新时间：2021 4 7
25 次查看（30 天）

0 个投票

I am not sure if I am supposed to be using linspace or not to ensure that vectors are the same length.
Vectors must be the same length is the error I cannot figure out. Here is the code(A picture is also provided that looks much more readable)
CODE STARTS BELOW:
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
clc
clear
close all
k = input('Enter the value of gain k = '); % (gain k = 9 is given in the que.)
wn = input('Enter the value of natural Frequency wn = '); % (natural frequency wn = 3 is given in the que)
% step response & pole plot for zeta = 3
zeta = 3;
num = [k*wn^2];
den = [1 6*zeta wn^2];
sys = tf(num,den);
%[y,t] = step(sys);
k= 9;
s= 0.1:0.1:2;
w= 3;
tiledlayout(1,2);
ax1 = nexttile;
ax2 = nexttile;
for i = 1:length(s)
y = stepResponse(k, s(i), w);
t = 0:0.05:6;
plot(ax1, t, y)
xlabel (ax1, 'Time (sec)'); ylabel(ax1, 'Amplitude');
title(ax1, 'Step Reponse');
all_roots = getPoles(k, s(i), w);
plot (ax2, all_roots(:, 1), all_roots(:, 2), 'o');
xlabel (ax2, 'Real Part'); ylabel(ax2, 'Imaginary Part');
title(ax2, 'Pole Locations in Complex Plane');
hold(ax2, 'on');
pause(0.25);
end
function y=stepResponse(a, b, c)
y=step(a, b, c);
end

请先登录，再回答此问题。

 采纳的回答

VBBV
VBBV 2021-4-6

0 个投票

%if true
t = linspace(0,6,length(s));%0:0.05:6;
What is size of variable s in workspace ?

7 个评论
显示 5更早的评论 隐藏 5更早的评论

VBBV
VBBV 2021-4-6
Put the above code line outside of for loop
Zack Hawkins
Zack Hawkins 2021-4-6
s= 0.1:0.1:2;
That is what s is defined to be. Is that what you are looking for? or the amount of elements in the array in s?
Zack Hawkins
Zack Hawkins 2021-4-6
I am getting the same error. Although this does point me in the right direction so thank you!
VBBV
VBBV 2021-4-7
编辑：VBBV 2021-4-7
The variables s and t are not of same size. They don't have same number of elements. Therefore y output of stepresponse is also different
VBBV
VBBV 2021-4-7
编辑：VBBV 2021-4-7
Inside the loop modify the following lines of code
%if true
y(i) = stepResponse(k, s(i), w);
plot(ax1,t(1:i),y(1:i))
And change the defintion of variable t to
%f true
t = linspace(0,6,length(s));%0:0.05:6;
Zack Hawkins
Zack Hawkins 2021-4-7
Error: Unable to perform assignment bc the indices on the left are not compatible with the size of the right side.
Did i place the code in the correct place? (2 pics below showing different placements of the code you provided). I get the same error in both cases.
I also tried doing this placement incase I misunderstood you:
I really appreciate the help. I just had a professor yell at me today for not remembering something he mentioned 11 weeks ago. Although it still isnt working yet, you gave me hope :)
VBBV
VBBV 2021-4-7
%f
y = stepResponse(k, s(i), w);
K(i) = y;
plot(ax1,t(1:i),K(1:i))
Ok. In that case output of stepresponse is singular value. So, you can try above

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Creating, Deleting, and Querying Graphics Objects 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by