Vector Arctangent (Inverse Tangent) (ATAN)

ATAN applies the inverse tangent (arctan) mathematical transformation to each value in a data series, returning angles in radians from -π/2 to +π/2. Unlike ASIN and ACOS which require bounded inputs, ATAN accepts any real number, making it more versatile for slope and rate calculations. ATAN is commonly used for converting rate-of-change values into angular measurements or calculating indicator slopes in radians.

Developers use ATAN for slope-based indicator calculations, converting momentum or rate-of-change values into angular representations. Particularly useful for measuring indicator steepness (LINEARREG_ANGLE uses similar concepts), creating adaptive thresholds based on slope, or building custom trend strength measures. Combine with SQRT for magnitude-angle decompositions or with other trig functions for complete angular analysis. Essential for custom momentum indicators using angular metrics.