Visual Basic 2005 in a Nutshell (In a Nutshell (OReilly))

2017-07-07 02:10:07

Atan2 Function

Class

System.Math

Syntax

Dim result As Double = Math.Atan2(y, x)

x (required; Double): The x-coordinate of a point
y (required; Double): The y-coordinate of a point

Description

The Atan2 function returns the arctangent of the ratio x/y in radians. This is the angle in the Cartesian plane formed by the x-axis and a vector starting from the origin (0,0) and terminating at the point (x, y). More specifically, the return value satisfies the following:

For (x, y) in quadrant 1, 0 < result < p/2.

For (x, y) in quadrant 2, p/2 < result < p.

For (x, y) in quadrant 3, p < result < p/2.

For (x, y) in quadrant 4, p/2 < result < 0.

Usage at a Glance

This is a shared member of the System.Math class, so it can be used without an instance.

Version Differences

The Atan2 function does not exist in VB 6.