Index exceeds array dimensions. Index value 9 exceeds valid range [1-1] for array 'm2'.

I have tried to solve my problem many times but matlab throws this error, someone can help me please.

Error: "Index exceeds array dimensions. Index value 9 exceeds valid range [1-1] for array 'm2'."

function [dd_theta1,dd_theta2]=ss_barra1(T1,T2,d_theta1,theta1,dd_theta2 ,d_theta2,theta2)

%Los valores de las constantes que definen al robot son:

l1 = 2; % longitud en metros

l2 = 1; % longitud en metros

g = 9.81; % aceleración de la gravedad m/s^2

m1 = 2; % masa en kg

m2 = 1; % masa en kg

dd_theta1=(T1-m2*(l1*l2*cos(theta2)+(l2^2))*dd_theta2+m2*l1*l2*sin(theta2)*(2*d_theta1*d_theta2+(d_theta2^2))+(m1+m2)*l1*g*cos(theta1)+m2*g*l2*cos(theta1+theta2))/(m1*(l1^2)+m2((l1^2)+2*l1*l2*cos(theta2)+(l2^2)));

dd_theta2=(T2-m2*(l1*l2*cos(theta2)+(l2^2))*dd_theta1-m2*l1*l2*sin(theta2)*(d_theta1^2)-m2*g*l2*cos(theta1+theta2))/(m2*(theta2^2));

Answer 1

[Walter Roberson]

m2((l1^2)

MATLAB has no implied multiplication. That is a request to index m2