Search results
Results from the WOW.Com Content Network
In mathematics, the binary logarithm (log 2 n) is the power to which the number 2 must be raised to obtain the value n.That is, for any real number x, = =. For example, the binary logarithm of 1 is 0, the binary logarithm of 2 is 1, the binary logarithm of 4 is 2, and the binary logarithm of 32 is 5.
The log base 2 can be used to anticipate whether a multiplication will overflow, since ⌈log 2 (xy)⌉ ≤ ⌈log 2 (x)⌉ + ⌈log 2 (y)⌉. [53] Count leading zeros and count trailing zeros can be used together to implement Gosper's loop-detection algorithm, [54] which can find the period of a function of finite range using limited resources ...
The graph of the logarithm base 2 crosses the x-axis at x = 1 and passes through the points (2, 1), (4, 2), and (8, 3), depicting, e.g., log 2 (8) = 3 and 2 3 = 8. The graph gets arbitrarily close to the y-axis, but does not meet it. Addition, multiplication, and exponentiation are three of the most fundamental arithmetic operations.
For example, log 10 10000 = 4, and log 10 0.001 = −3. These are instances of the discrete logarithm problem. Other base-10 logarithms in the real numbers are not instances of the discrete logarithm problem, because they involve non-integer exponents. For example, the equation log 10 53 = 1.724276… means that 10 1.724276… = 53.
The identities of logarithms can be used to approximate large numbers. Note that log b (a) + log b (c) = log b (ac), where a, b, and c are arbitrary constants. Suppose that one wants to approximate the 44th Mersenne prime, 2 32,582,657 −1. To get the base-10 logarithm, we would multiply 32,582,657 by log 10 (2), getting 9,808,357.09543 ...
It may also refer to the binary (base 2) logarithm in the context of computer science, particularly in the context of time complexity. Generally, the notation for the logarithm to base b of a number x is shown as log b x. So the log of 8 to the base 2 would be log 2 8 = 3.
The convex conjugate (specifically, the Legendre transform) of the binary entropy (with base e) is the negative softplus function. This is because (following the definition of the Legendre transform: the derivatives are inverse functions) the derivative of negative binary entropy is the logit, whose inverse function is the logistic function ...
Download QR code; Print/export Download as PDF; ... Using base-2 logarithms: pmi(x=0;y=0) ... instead of log base 2) word 1 word 2 count word 1 count word 2 count of ...