Language reference
Atn (arctangent)
Syntax
Atn(<number>)
π Atn(slope) → angle_rad (Lines)Description
Atn returns the arctangent — the angle (in radians) whose tangent is the input. It is the inverse of Tan, useful for recovering an angle from a slope or ratio.
Technical Description
Atn(x: NUMBER) → NUMBER. Returns atan(x) in radians, in the range (−π/2, π/2) (Math.atan). NULL input returns NULL. PURE, DETERMINISTIC. Floating-point result.
Examples
Angle of a slope, in radians:
π Atn(rise / run) → angle_rad (Lines)PROJECT Atn(rise / run) -> angle_rad (Lines)Convert the result to degrees:
π Atn(slope) * 180 / 3.14159265 → angle_deg (Lines)PROJECT Atn(slope) * 180 / 3.14159265 -> angle_deg (Lines)Limitations
Returns radians in (−π/2, π/2). NUMBER only; NULL in → NULL out. Single-argument form only (no two-argument atan2). Floating point.
Alternatives
Tan is the forward direction (angle → ratio).