Function atan() calculates the radian of a tangent value.

Arguments：

• Tangent <number>

Returns：

• Radian <number>, ∈ [-PI/2, PI/2]

Common Usage

Example: calculate the radian when the given tangent value is 1

return atan(1) * 180 / pi()

Example: calculate the radians of a column of tangent values

uncollect [1, -0.5, 0] as a
return atan(a)