ConceptPythonIntermediate Finite volumes: why a conservation law is solved by bookkeeping the fluxes sech2 = lambda z: 1 / np.cosh(z)**2
ToolPythonAdvanced Fourier spectral method for KdV: two solitons pass through each other return 0.5 * c / np.cosh(0.5 * np.sqrt(c) * (x - x0))**2S, tau = 1 / np.cosh(a * x)**2, np.tanh(a * x)