Guys, need help with matlab: can't plot graph (differential equations)

Thread Starter

Gudsaf

Joined May 23, 2013
1
So, good day.
I had problem with matlab: can't plot graph.
Need to say u, i from Russia, maybe my language bad, so sorry))
Maybe u can give advice - where (what forum) can help me?

My equation:
??????.PNG
My code:
Rich (BB code):
T = [0 5e-6];
i0 = [0 0];
[t, I] = ode45('qweq',T,i0);
    % печатаем график i(t) / print i(t)
    figure
    plot(t,I(:,1))
    grid on
    legend('i(t)')
    xlabel('t')
    ylabel('i')
    title('График зависимости тока от времени')
    % печатаем график di/dt / print di/dt
    figure
    plot(t,I(:,2))
    grid on
    legend('di/dt')
    xlabel('dt')
    ylabel('di')
    title('График зависимости di по dt')
Function:
Rich (BB code):
function F = qweq(t,I)
    R0 = 2;
    L = 1e-6;
    C = 0.001e-6;
    f = 1e6;
    k = 8e10;
    Um = 1;
 
w = 2*pi*f;
R = R0*(1-k*I(1)^2);
 
F = zeros(2,1);
F(1) = I(2);
F(2) = ( Um*w*cos(w*t) - (1/C)*I(1) - R*I(2) )/L;
if i set k as 0, all ok. But in task k must be 8e10...
 
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