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differential-equationsscilab

Simple second order ODE in Scilab

I am very new to scilab and am trying to understand how ODE works for second order ODE works in SCILAB.

My Equation is: (d^2y)/(dt^2 )+2 dy/dt + y=0

I would like to plot the results. So far I have understood I need to break down the equations in to two first order equations. So the program must look like:

function dx=f(x, y)
    dx(1)=2*y+1;
    dx(2)=y;
endfunction

Can you check if this is correct, I am not sure if dx(1) and dx(2) is correct.

Thank you.

Solution

  • If x_1 is y and x_2 is dy/dt you would rather write your ode right hand side (i.e. dx/dt) like this

    function dxdt=f(t, x)
    dxdt(1) =  x(2);
    dxdt(2) = -x(1)-2*x(2);
endfunction