ellippy.misc.heuman_lambda#
- ellippy.misc.heuman_lambda(phi, m)[source]#
Computes Heuman Lambda function Λ₀(φ | m).
\[\Lambda_0(\varphi, m) = \frac{F\!\left(\varphi, 1-m\right)}{K\!\left(1-m\right)} + \frac{2}{\pi} K(m)\, Z\!\left(\varphi, 1-m\right)\]- Parameters:
phi (
ArrayLike) – Amplitude angle (φ) in radians. φ ∈ ℝ.m (
ArrayLike) – Elliptic parameter. m ∈ ℝ, 0 ≤ m < 1.
- Returns:
Scalar or numpy.ndarray broadcast from inputs.
- Raises:
ValueError – If m < 0 or m ≥ 1, phi is infinite, or inputs contain NaN.
Graph
Special Cases
Λ₀(nπ/2, m) = n where n ∈ ℤ
Λ0(φ, 0) = sin(φ)
Related Functions
- With mc = 1 - m and Δ² = 1 - mc sin²φ:
Λ₀(φ, m) = F(φ, mc)/K(mc) + (2/π) K(m) Z(φ, mc)
Λ₀(φ, m) = 2/π · mc sin(φ) cos(φ)/Δ · [RF(0, mc, 1) + m/(3Δ²) RJ(0, mc, 1, 1 - m/Δ²)]
References
Maddock, John, Paul Bristow, Hubert Holin, and Xiaogang Zhang. “Boost Math Library: Special Functions - Elliptic Integrals.” Accessed August 30, 2025. https://www.boost.org/doc/libs/1_88_0/libs/math/doc/html/math_toolkit/ellint.html.
Pornsiriprasert, Sira. Ellip: Elliptic Integrals for Rust. V. 0.5.1. Released October 10, 2025. https://docs.rs/ellip/0.5.1/ellip/index.html.