Programming Ruby

The Pragmatic Programmer's Guide

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module Math


atan2 cos exp frexp ldexp log log10 sin sqrt tan

The Math module contains module functions for basic trigonometric and transcendental functions.


E 2.718281828 Value of e (base of natural logarithms)
PI 3.141592654 Value of PI

class methods
atan2 Math.atan2( y, x ) -> aFloat

Computes the arc tangent given y and x. Returns -PI..PI.

cos Math.cos( aNumeric ) -> aFloat

Computes the cosine of aNumeric (expressed in radians). Returns -1..1.

exp Math.exp( aNumeric ) -> aFloat

Returns e raised to the power of aNumeric.

frexp Math.frexp( aNumeric ) -> anArray

Returns a two-element array ([aFloat, aFixnum]) containing the normalized fraction and exponent of aNumeric.

ldexp Math.ldexp( aFloat, anInteger ) -> aFloat

Returns the value of aFloat *2 anInteger .

log Math.log( aNumeric ) -> aFloat

Returns the natural logarithm of aNumeric.

log10 Math.log10( aNumeric ) -> aFloat

Returns the base 10 logarithm of aNumeric.

sin Math.sin( aNumeric ) -> aFloat

Computes the sine of aNumeric (expressed in radians). Returns -1..1.

sqrt Math.sqrt( aNumeric ) -> aFloat

Returns the non-negative square root of aNumeric. Raises ArgError if aNumeric is less than zero.

tan Math.tan( aNumeric ) -> aFloat

Returns the tangent of aNumeric (expressed in radians).

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Extracted from the book "Programming Ruby - The Pragmatic Programmer's Guide"
Copyright © 2001 by Addison Wesley Longman, Inc. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at

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