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.

Math.log(x)

x

Es un numero.

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

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) .

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.

• Math.exp()
• Math.log1p() (en-US)
• Math.log10()
• Math.log2()
• Math.pow()