Lotka-Volterra equation solver

This webpage uses the Runge-Kutta-Fehlberg fourth-order method with fifth-order error checking (RKF45) to approximate the solution to Lotka-Volterra equations: \[ \begin{aligned} \dfrac{dx}{dt} &= \alpha x - \beta xy \\ \dfrac{dy}{dt} &= \delta xy - \gamma y \end{aligned} \] where \(x\) is the number of prey animals and \(y\) is the number of predator animals and \(\alpha, \beta, \gamma\), and \(\delta\) describe their interactions with one another.