Numerical Analysis, Numerical Methods, Stability Test.
Fourier mode at the current time step to the amplitude of the Fourier mode at the previous time step. ∣∣∣λΔtλ0∣∣∣≤1 where λΔt is the amplification factor at time step Δt, λ0 is the amplification factor at time step 0, and the absolute value of the fraction of these two factors must be less than or