Not enough input arguments
4 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Gopika R
le 30 Juin 2020
Commenté : Walter Roberson
le 1 Juil 2020
function xdot = OD(t,x)
global A B C Da K
Aa=A+(B*K*C);
Ba=B*Da;
u=K*x;
xdot=(Aa*x)+(Ba*u);
end
When running this code it show error in the line u=K*x; as not enough inputs. Here A,B,C,Da,K are all 2x2 matrix.
8 commentaires
Walter Roberson
le 1 Juil 2020
When you use the green run button, then where are you expecting that MATLAB will look for the values of t and x to use inside the routine?
Réponse acceptée
Ameer Hamza
le 1 Juil 2020
It seems that you are trying to solve a matrix differential equation. If you are using ode45, one possible way this error can occur if you call it like this
ode45(@(t,x) OD, [0 10], [1; -1; 0; 0])
The correct syntax is
ode45(@(t,x) OD(t,x), [0 10], [1; -1; 0; 0]) % or
ode45(@OD, [0 10], [1; -1; 0; 0])
The following shows working code with random values for matrices
global A B C Da K
A = rand(4);
B = rand(4);
C = rand(4);
Da = rand(4);
K = rand(4);
ode45(@(t,x) OD, [0 10], [1; -1; 0; 0])
function xdot = OD(t,x)
global A B C Da K
Aa=A+(B*K*C);
Ba=B*Da;
u=K*x;
xdot=(Aa*x)+(Ba*u);
end
Also, using global variables is not a good coding practice. Following shows how to pass these matrices to function OD without using global
A = rand(4);
B = rand(4);
C = rand(4);
Da = rand(4);
K = rand(4);
ode45(@(t,x) OD(t,x,A,B,C,Da,K), [0 10], [1; -1; 0; 0])
function xdot = OD(t,x,A,B,C,Da,K)
Aa=A+(B*K*C);
Ba=B*Da;
u=K*x;
xdot=(Aa*x)+(Ba*u);
end
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Whos dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!