Lobachevsky Function Calculator
Free online lobachevsky function calculator. Enter your values and get instant results with the formula, step-by-step working, a worked example and FAQs — everything runs locally in your browser on Calcton, no signup required.
Lobachevsky 函数 Λ(θ) = −∫₀^θ ln(2·sin t) dt 是双曲几何的「体积元」：理想双曲四面体若二面角为 α、β、γ 及其配对，则体积正比于 Λ 的组合（Murakami–Yano 公式）；理想三角形的面积恰好是 π − (α+β+γ) 的 Λ 表达。它也是结理论中双曲结补空间体积的主角，与 Clausen 函数满足 Λ(θ) = ½Cl₂(2θ)。
数值实现利用「减奇性」拆分：ln(2·sin t) = ln t + ln(2·sin t/t)，前者解析积出 θ(lnθ − 1)，后者在原点光滑（极限 ln 2）交给 8000 段 Simpson。这个手法让 Λ(10⁻⁶) 也有满精度。
参考值
Λ(π/4) = G/2 = 0.457982797088610（G 为 Catalan 常数 0.915965594177219）
Λ(π/6) = ½Cl₂(π/3) = 0.507470803204827，Λ(π/2) = 0，Λ(π/3) = 0.338313868803218
Λ(3π/4) = −G/2（对称性 Λ(π−θ) = −Λ(θ)）
How to use the Lobachevsky Function Calculator
- Fill in the inputs with your own numbers — every field shows what it expects.
- The result updates instantly as you type; no "Calculate" click needed.
- Read the result card for the main figure, the step-by-step formula, and practical notes.
Frequently asked questions
Is the Lobachevsky Function Calculator free?
Yes — all math calculators on Calcton are free, with no sign-up required. Your inputs are processed in your browser and never sent to a server.
Is there a Chinese version of this tool?
Yes. Use the Chinese version link above — it is the same calculator with the interface in Simplified Chinese.
References
Formulas and benchmarks used by this calculator follow these published sources.
KevinContent LeadCalcton Editorial Team · Last updated 2026-09-27
Kevin maintains Calcton's formula verification and content: every calculator cites the standard it implements, worked examples are recomputed programmatically, and health benchmarks follow WHO and international guidelines.
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