Help on using ode45

Question

maritrad 2017-3-20

0
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https://ww2.mathworks.cn/matlabcentral/answers/330851-help-on-using-ode45

评论： maritrad 2017-3-20

Hello! I am trying to solve a system of differential equations using ode45 and I only get as a result NaN numbers. I am quite new on Matlab, can somebody help me? :)

My code is:

    A = 0.3; 
    f = @(t,x) [x(2)*x(3)*sin(x(6)-x(5)-x(4)-A*t);...
               x(1)*x(3)*sin(x(6)-x(5)-x(4)-A*t); ...
               -2*x(2)*x(1)*sin(x(6)-x(5)-x(4)-A*t); ...
               -x(1)^-1*x(2)*x(3)*cos(x(6)-x(5)-x(4)-A*t); ...
                -x(2)^-1*x(1)*x(3)*cos(x(6)-x(5)-x(4)-A*t); ...
                -2*x(3)^-1*x(2)*x(1)*cos(x(6)-x(5)-x(4)-A*t)]
    [t,xa] = ode45(f,[0.01 1],[sqrt(20) sqrt(0.1*20) 0 0 0 0]);