Math.log()

La función Math.log() devuelve la base neutral de un número (base e)

$\forall x > 0, \mathtt{\operatorname{Math.log}(x)} = \ln(x) = \text{el unico} ; y ; \text{tal que} ; e^y = x$

La función en JavaScrcrip Math.log() es equivalente a ln(x) en matematicas.

Sintaxis

Math.log(x)

Retorna el valor

La base natural (base e) del número dado. Si el número es negativo, se devuelve NaN

Descripcion

If the value of x is negative, the return value is always NaN.

Because log() is a static method of Math, you always use it as Math.log(), rather than as a method of a Math object you created (Math is not a constructor).

If you need the natural log of 2 or 10, use the constants Math.LN2 or Math.LN10 . If you need a logarithm to base 2 or 10, use Math.log2() or Math.log10() . If you need a logarithm to other bases, use Math.log(x) / Math.log(otherBase) as in the example below; you might want to precalculate 1 / Math.log(otherBase) .

Examples

Using `Math.log()`

Math.log(-1); // NaN, out of range
Math.log(0);  // -Infinity
Math.log(1);  // 0
Math.log(10); // 2.302585092994046

Using `Math.log()` with a different base

The following function returns the logarithm of y with base x (ie. $\log_x y$ ):

function getBaseLog(x, y) {
  return Math.log(y) / Math.log(x);
}

If you run getBaseLog(10, 1000) it returns 2.9999999999999996 due to floating-point rounding, which is very close to the actual answer of 3.

Especificaciones

Specification
ECMAScript Language Specification # sec-math.log

Browser compatibility

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