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ATAN2()

Two-argument arc tangent

Result type

DOUBLE PRECISION

Syntax
ATAN2 (y, x)
Table 1. ATAN2 Function Parameters
Parameter Description

y

An expression of a numeric type

x

An expression of a numeric type

Returns the angle whose sine-to-cosine ratio is given by the two arguments, and whose sine and cosine signs correspond to the signs of the arguments.This allows results across the entire circle, including the angles -pi/2 and pi/2.

  • The result is an angle in the range [-pi, pi].

  • If x is negative, the result is pi if y is 0, and -pi if y is -0.

  • If both y and x are 0, the result is meaningless.An error will be raised if both arguments are 0.

  • A fully equivalent description of this function is the following: ATAN2(y, x) is the angle between the positive X-axis and the line from the origin to the point (x, y).This also makes it obvious that ATAN2(0, 0) is undefined.

  • If x is greater than 0, ATAN2(y, x) is the same as ATAN(y/x).

  • If both sine and cosine of the angle are already known, ATAN2(sin, cos) gives the angle.

ATANH()

Inverse hyperbolic tangent

Result type

DOUBLE PRECISION

Syntax
ATANH (number)
Table 1. ATANH Function Parameter
Parameter Description

number

Any non-NULL value in the range <-1, 1>.

The result is a number in the range [-INF, INF].