User Guide

442 Chapter 2: ActionScript Language Reference

Math.sin()

Availability

Flash Player 5. In Flash Player 4, the methods and properties of the Math class are emulated using

approximations and might not be as accurate as the non-emulated math functions that Flash

Player 5 supports.

Usage

Math.sin(x:Number) : Number

Parameters

A number that represents an angle measured in radians.

Returns

A number; the sine of the specified angle (between -1.0 and 1.0).

Description

Method; computes and returns the sine of the specified angle in radians. To calculate a radian, see

“Description” on page 419 of the Math class entry.

Example

The following example draws a circle using the mathematical constant pi, the sine of an angle,

and the Drawing API.

drawCircle(this, 100, 100, 50);

function drawCircle(mc:MovieClip, x:Number, y:Number, r:Number):Void {

mc.lineStyle(2, 0xFF0000, 100);

mc.moveTo(x+r, y);

mc.curveTo(r+x, Math.tan(Math.PI/8)*r+y, Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, r+y, x, r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, r+y, -Math.sin(Math.PI/4)*r+x,

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-r+x, Math.tan(Math.PI/8)*r+y, -r+x, y);

mc.curveTo(-r+x, -Math.tan(Math.PI/8)*r+y, -Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(-Math.tan(Math.PI/8)*r+x, -r+y, x, -r+y);

mc.curveTo(Math.tan(Math.PI/8)*r+x, -r+y, Math.sin(Math.PI/4)*r+x, -

Math.sin(Math.PI/4)*r+y);

mc.curveTo(r+x, -Math.tan(Math.PI/8)*r+y, r+x, y);

}