Section 24.113. Math.log( ): compute a natural logarithm


24.113. Math.log( ): compute a natural logarithm

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24.113.1. Synopsis

Math.log(x)

24.113.1.1. Arguments

x

Any numeric value or expression greater than zero.

24.113.1.2. Returns

The natural logarithm of x.

24.113.2. Description

Math.log( ) computes logex, the natural logarithm of its argument. The argument must be greater than zero.

You can compute the base-10 and base-2 logarithms of a number with these formulas:

 log10x  = log10e · logex log2x  = log2e · logex 

These formulas translate into the following JavaScript functions:

 function log10(x) { return Math.LOG10E * Math.log(x); } function log2(x) { return  Math.LOG2E * Math.log(x); } 




JavaScript. The Definitive Guide
JavaScript: The Definitive Guide
ISBN: 0596101996
EAN: 2147483647
Year: 2004
Pages: 767

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