Advanced math
ODEs, transforms, special functions, and fields
Fourier series
Square-wave partial sums
Complex algebra
Polar, powers, roots
Bessel J₀/J₁
Cylindrical special functions
ODE RK4
y′=f(y) integrator
2D field map
Sample harmonic-like field
Legendre Pₗ
Polynomial evaluation
Discrete spectrum
DFT magnitude toy
Gradient descent
1D quadratic steps
Vector calculus toy
div/curl of F=(−y,x,z)
Yₗₘ angular shape
Unnormalized θ-shape (not |Y|)