Vectors must be the same length.

Question

Nasser Aljadeed 2015-9-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/244720-vectors-must-be-the-same-length

编辑： Image Analyst 2021-4-3

Every time I run this code, I get "Error using plot Vectors must be the same length.

Error in ex (line 24) plot(t,abs(Y)) "

Here is my code:

clear

dt = 1/100000;

tstart = 0;

tend = 0.020;

t=[tstart : dt : tend];

xc=25*sin(2*pi*150*t)-15*cos(2*pi*800*t);

T = 0.00025;

n = [tstart/T : tend/T];

x1=25*sin(2*pi*150*n*T)-15*cos(2*pi*800*n*T);

% Quantize Signal

x2=fix(x1);

% Define filter coefficents

A = [1];

B = [1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16];

% Filter the quantize signal

Y = filter(B,A,x2);

figure(1)

subplot(211)

plot(t,abs(Y))

xlabel('Frequency (rad/sec)')

ylabel('Magntidue')

subplot(212)

plot(t,angle(Y))

xlabel('Frequency (rad/sec)')

ylabel('Phase')

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Answer 1

the cyclist 2015-9-23

3
链接

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https://ww2.mathworks.cn/matlabcentral/answers/244720-vectors-must-be-the-same-length#answer_193475

The proximate cause of your problem is that you are trying to make an X-Y plot, where X (your variable "t") has 2001 elements, and Y has 81 elements. So, MATLAB cannot figure out how plot each (X,Y) pair, because the two vectors do not have an equal number of points.

It is not easy for me to figure out what you intended to do.

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Nasser Aljadeed 2015-9-23

How can I make these vectors have the same dimensions?

So : t =[tstart : dt : tend] has to have the same dimensions as n = [tstart/T : tend/T]?

the cyclist 2015-9-24

编辑：the cyclist 2015-9-24

Probably the easiest way to ensure an equal number of elements, and uniform spacing, is to use the linspace command to create both vectors.

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Answer 2

Jae Song 2015-9-23

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/244720-vectors-must-be-the-same-length#answer_193477

编辑：Jae Song 2015-9-23

在 MATLAB Online 中打开

It looks like the variables xc and t have same size. So if you let x2 = fix(xc) instead of x2 = fix(x1). The plot should work. (I don't know that was your intention or not)

clear
dt = 1/100000;
tstart = 0;
tend = 0.020;
t=[tstart : dt : tend];
xc=25*sin(2*pi*150*t)-15*cos(2*pi*800*t);
T = 0.00025;
n = [tstart/T : tend/T];
x1=25*sin(2*pi*150*n*T)-15*cos(2*pi*800*n*T);
% Quantize Signal
x2=fix(xc);
% Define filter coefficents
A = [1];
B = [1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16 1/16];
% Filter the quantize signal
Y = filter(B,A,x2);
figure(1);
subplot(211);
plot(t,abs(Y))
xlabel('Frequency (rad/sec)')
ylabel('Magntidue')
subplot(212)
plot(t,angle(Y))
xlabel('Frequency (rad/sec)')
ylabel('Phase')