al">&gt;</span></code>
        as the state type, but others are also possible, for example <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">,</span><span class="number">2</span><span class="special">&gt;</span></code>. odeint is designed in such a way that
        you can easily use your own state types. Next, the ODE is defined which