3 ms·

This is very common. Log without further specification can be assumed to be the natural log (log e).

• griffzhowl 1y ago
  In information theory it usually means log base 2
• eviks 1y ago
  no, that's what ln is for
  • thaumasiotes 1y ago
    Well, you're right that that's what "ln" is for. But more specifically "ln" is for indicating the natural log on calculators that already have another button labeled "log". Tarq0n is correct that "log" without further specification can be assumed to be the natural log.
• holowoodman 1y ago
  No. Usually log without further specification is base10. Except in mathematics and physics, where it usually is base e. Except sometimes in computer science, where it can be base 2. But there are more of those weirdnesses: "ld" can be "log decimal", so base 10; or "logarithmus dualis", so base 2. Base 2 is also sometimes written as "lb" (log binary). You really need to know the conventions of the field/subfield to know which is which.
  • eru 1y ago
    Log without a basis (at least to me) usually indicates that the basis doesn't matter in this context (or is obvious). I usually see either base e or base 2 as the default. In which applications do people use both logarithms and base 10 as the default? I mean, especially these day. In the olden days of the slide ruler base 10 was probably more common.
    • holowoodman 1y ago
      > In which applications do people use both logarithms and base 10 as the default? Engineering. For example dB is defined in base 10.
  • gbacon 1y ago
    Base 2 is also sometimes abbreviated lg.
• mort96 1y ago
  In this case, and in many other cases, log without further specification is meant to be understood as just "it is logarithmic" without further specification. With big O, we don't differentiate between log bases, just as we don't differentiate between scale factors. In fact, converting from one log base to another is just multiplying by a constant.