Help with ODE solving using RK method in Matlab











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I have the following ode



$idot{x_n}(t)=-x_{n+1}(t)-x_{n-1}(t)+g~ x_n(t)$ with I.C. $phi(0)=-2cos(2.5)$ and $g=1$.



where $dot{x_n}=frac{dx_n}{dt}$, $n$ are discrete points in space, and $x$ is the value of field on each point.



However, I am unable to produce desired plot of $x_n$ (at a fixed time) along y-axis vs $n$ on x-axis.
I am trying to solve it via Matlab ODE45 but unable to get around it. We could take say $-5leq nleq5$, i.e., 11 total space points to start. Thanks






differential-equations numerical-methods matlab







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    up vote
    -1
    down vote

    favorite












    I have the following ode



    $idot{x_n}(t)=-x_{n+1}(t)-x_{n-1}(t)+g~ x_n(t)$ with I.C. $phi(0)=-2cos(2.5)$ and $g=1$.



    where $dot{x_n}=frac{dx_n}{dt}$, $n$ are discrete points in space, and $x$ is the value of field on each point.



    However, I am unable to produce desired plot of $x_n$ (at a fixed time) along y-axis vs $n$ on x-axis.
    I am trying to solve it via Matlab ODE45 but unable to get around it. We could take say $-5leq nleq5$, i.e., 11 total space points to start. Thanks






    differential-equations numerical-methods matlab







    share|cite|improve this question
























      up vote
      -1
      down vote

      favorite









      up vote
      -1
      down vote

      favorite











      I have the following ode



      $idot{x_n}(t)=-x_{n+1}(t)-x_{n-1}(t)+g~ x_n(t)$ with I.C. $phi(0)=-2cos(2.5)$ and $g=1$.



      where $dot{x_n}=frac{dx_n}{dt}$, $n$ are discrete points in space, and $x$ is the value of field on each point.



      However, I am unable to produce desired plot of $x_n$ (at a fixed time) along y-axis vs $n$ on x-axis.
      I am trying to solve it via Matlab ODE45 but unable to get around it. We could take say $-5leq nleq5$, i.e., 11 total space points to start. Thanks






      differential-equations numerical-methods matlab







      share|cite|improve this question













      I have the following ode



      $idot{x_n}(t)=-x_{n+1}(t)-x_{n-1}(t)+g~ x_n(t)$ with I.C. $phi(0)=-2cos(2.5)$ and $g=1$.



      where $dot{x_n}=frac{dx_n}{dt}$, $n$ are discrete points in space, and $x$ is the value of field on each point.



      However, I am unable to produce desired plot of $x_n$ (at a fixed time) along y-axis vs $n$ on x-axis.
      I am trying to solve it via Matlab ODE45 but unable to get around it. We could take say $-5leq nleq5$, i.e., 11 total space points to start. Thanks






      differential-equations numerical-methods matlab




      differential-equations numerical-methods matlab






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










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