Clicking the jsRK4 example links in following table will present an HTML5 compatible web page displaying the dynamic response of an ideal vertical mass-spring-damper system. The disguishing features of each example involve graphics displayed, complexity of user interface and structure of associated JavasScript code as denoted.
| Link | Description |
|---|---|
| Example 1 | Dynamic response plot with simulation start and gravity enable/disable buttons. |
| Example 2 | Dynamic response plot and mass-spring-damper animation, but with no user inputs. |
| Example 3 | Dynamic response plot, mass-spring-damper animation, simulation start/resume, stop/pause and reset buttons, input fields for system characterizing parameters and integration time increment values; uses object-oriented JavaScript code. |
| Example 4 | Same as Example 2, but uses object-oriented JavaScript code. |
Refactoring of JavaScript code embedded in Examples 1 and 2 into object-oriented components contained in three class files -- rk4solver.js, system_mass_spring_damper.js and canvas_graph.js -- enhances the modularity of the simulation code. This improves maintainability by reducing amount of duplicative code and promotes resusability through separation of functionality. The rk4solver class is for applying RK4 integration method on a given system of first order differential equations. The system_mass_spring_damper class characterizes the physical system to be simulated, and the canvas_graph class is for graphing data in a XY plot on the given canvas.