Data must be a single matrix Y or a list of pairs X,Y. Need help on plotting 3D graph!

 array= Tmax/n;                                      %This expends the data points n = 2000 and Tmax = 20
t = 0:array:Tmax;                                  %This sets the time interval
e = 2.71828;                                       %e's true value
y1 = A0*e.^(-LamdaR.*t).*cos(LamdaI.*t);           %This is the position function x(t)
y2 = -A0*LamdaI*e.^(-LamdaR*t).*((sin(LamdaI*t)+((LamdaR/LamdaI))*cos(LamdaI*t))); 
                                                    %equation above is the speed
                                                    %equation (dx/dt)
plot(y1,y2,t),xlabel('x'),ylabel('dx/dt'),zlabel('time'),grid;

i am trying to ploy a 3d graph but keep on getting an error that says Data must be a single matrix Y or a list of pairs X,Y. please help?

[John BG]

Hi Petronas

this is John BG <mailto:[e-mail] [e-mail]>

I was just doing some guessing with the code you posted in the question

n=2000
Tmax=20
A0=1
array= Tmax/n;                                      %This expends the data points n = 2000 and Tmax = 20
t = 0:array:Tmax;                                  %This sets the time interval
e = 2.71828;                                       %e's true value
y1 = A0*e.^(-LamdaR.*t).*cos(LamdaI.*t);           %This is the position function x(t)
y2 = -A0*LamdaI*e.^(-LamdaR*t).*((sin(LamdaI*t)+((LamdaR/LamdaI))*cos(LamdaI*t))); 
                                                    %equation above is the speed
                                                    %equation (dx/dt)
plot(y1,y2,t),xlabel('x'),ylabel('dx/dt'),zlabel('time'),grid;

when the code has been removed. Would you please be so kind to let know what are LambdaR and LamdaI, no need for real data, but are the 1xN vectors?

same length as t?

[Walter Roberson]

PetronasAMG: if you need privacy for your questions then you should be hiring a consultant. The MATLAB Answers facility is for volunteers sharing questions and solutions; questions remain on the record so that other people with similar questions can learn from the questions and solutions. We volunteers donate our time to help everyone, for the public good, not for the individual good; lack of privacy is the price you have to pay.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Star Strider]

Use the plot3 (link) function instead:

plot3(y1,y2,t),xlabel('x'),ylabel('dx/dt'),zlabel('time'),grid;

[Steven Lord]

Also you should use the exp function instead of trying to define e yourself.