Heat, Wave, and Laplace equations.
Simulates second-order linear PDEs in 1D space: (1) 1D Heat / Diffusion Equation (Parabolic): \(u_t = \alpha u_{xx}\), modeling thermal dissipation, solved via FTCS explicit finite differences with Courant-Friedrichs-Lewy (CFL) stability condition \(r = \frac{\alpha \Delta t}{\Delta x^2} \le \frac{1}{2}\); (2) 1D Wave / Vibration Equation (Hyperbolic): \(u_{tt} = c^2 u_{xx}\), modeling acoustic and string oscillations, with d'Alembert traveling wave solution \(u(x,t) = f(x-ct) + g(x+ct)\).