The quasiperiodic function defined by d/(d z) ln σ(z;g_2, g_3) = ζ(z;g_2, g_3), where ζ(z;g_2, g_3) is the Weierstrass zeta function and lim_(z->0) (σ(z))/z = 1.

Weierstrass constant | Weierstrass elliptic function | Weierstrass zeta function