MATLAB: How to plot a Differential Equation

differential equationsdsolvesymbolicSymbolic Math Toolbox

How do you plot this differential equation on matlab?

C(dV/dt) = I(t) – V(t)/R

Where C= 100e-12 F

R = .6e-9 Ohms

Vrest = -65e-3 V

And I(t) is ay simple function of t (I=t)

And we are solving for V

Best Answer

syms V(t)
C=...
R=...
Vrest=...
ode=C*diff(V)==t-V/R;
V(t)=dsolve(ode,V(0)==Vrest);
fplot(V(t))

Related Solutions

MATLAB: How to Plot Multivariate Differential Equation in MATLAB

The symbolic approach:

syms  I R V(t) t V0 
I = sym(50E-9);
R = sym(200E+6);
C = sym(50E-12);
Eq = V == I*R - R*C*diff(V);
Vs(t) = dsolve(Eq, V(0) == 0)
figure
fplot(Vs, [0, 0.1])
grid

Experiment to get the result you want.

MATLAB: Solve system of differential equations with vector input

In the derivation, let ‘a’ simply be an undefined constant, and define the initial conditions as 0 (unless you want them to be something else). Then in the solution, provide ‘a’ as a row vector to get the solution:

syms A B u(t) v(t) a
ode1 = diff(u,t) == A * (a - u);
ode2 = diff(v,t) == B * (u - v);
odes = [ode1; ode2];
[uSol(t), vSol(t)] = dsolve(odes, u(0)==0, v(0)==0)
% Above work fine; below don't
uF = matlabFunction(uSol);
vF = matlabFunction(vSol);
av = randn(1, 11);
resultu = uF(0:10, 1, 2, av); % t, A, B
resultv = vF(0:10, 1, 2, av);

This evaluates them as functions of whatever you want to define ‘a’ to be.

Best Answer

Related Solutions

MATLAB: How to Plot Multivariate Differential Equation in MATLAB

MATLAB: Solve system of differential equations with vector input

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