Vector Arcsine (Inverse Sine) (ASIN)

ASIN applies the inverse sine (arcsin) mathematical transformation to each value in a data series, returning angles in radians. For input x where -1 ≤ x ≤ 1, ASIN returns values from -π/2 to +π/2. This trigonometric transform is used in custom indicator calculations requiring phase angle derivation or converting normalized oscillator readings into angular representations. ASIN is typically applied to indicator outputs rather than raw price data.

Developers use ASIN when building custom cycle indicators, phase calculations, or advanced technical analysis algorithms requiring angle transformations. It's particularly useful for deriving phase relationships in quadrature systems or converting bounded oscillator values into phase angles. Combine with ACOS, SIN, and COS for complete trigonometric indicator systems. Essential for custom Hilbert Transform-based indicators or adaptive cycle analysis tools.