Lb

The binary logarithm of z, identical to Log2.

✓ checked against that system · ! checked, with disagreements (hover a chip)WikipediaBinary logarithm↗MathWorldBinaryLogarithm↗WikidataQ581168↗Wolfram LanguageLog2✓↗

Lb(z)the base-2 logarithm of z, $\log_2(z)$.

SageMathlog(z, 2)✓↗SymPylog(z, 2)↗mpmathlog(z, 2)↗Juliaenumeratio_ball(_log2, z)Rustlog2(z)

Typed signatures

Type	Package	Applies
(number) -> number	compute-engine	always

Domain: Elementary functions

Details

• An alias for Log2 -- the "lb" notation is borrowed from information theory and computer science, as opposed to "lg" for base 10.
• $\mathrm{Lb}$ is the binary logarithm, identical to Log2.

Plot

Examples

Basic #

live ↗

In$\log_{2}(8)$Out$3$

live ↗

In$\log_{2}(1)$Out$0$

live ↗

In$\log_{2}(1\,024)$Out$10$

A machine-precision argument evaluates numerically

live ↗

In$\log_{2}(1.414\,2)$Out$0.499\,986\,164\,421\,874\,256\,467$

live ↗

In$\log_{2}(2^{10})$Out$10$

Scope #

Same exact negative power fold as Log2: $\operatorname{lb}\tfrac18 = -3$

live ↗

In$\log_{2}(\frac{1}{8})$Out$-3$

live ↗

In$\log_{2}(0)$Out$-∞$

Threads element-wise over a list

live ↗

In$\log_{2}(\bigl\lbrack1, 2, 4, 8\bigr\rbrack)$Out$\bigl\lbrack0, 1, 2, 3\bigr\rbrack$

Same as Log2: the logarithm of complex infinity is $+\infty$

live ↗

In$\log_{2}(\tilde∞)$Out$∞$

Properties #

Identical to Log2

live ↗

In$\log_{2}(64)=\log_{2}(64)$Out$\mathrm{True}$

About

Examples	10
Checked against	Wolfram Language 10 agreeSageMath 10 agreeSymPy 8 agree2 differmpmath 9 agreeJulia 8 agree1 errorRust 8 agree1 error
Crosswalk	WikipediaMathWorldWikidataWolfram LanguageSageMathSymPympmathJuliaRust

Implementation

mappedsympypackages/oracle/src/mappings.ts

mappedmpmathpackages/oracle/src/mappings.ts

mappedsagepackages/oracle/src/mappings.ts

mappedjuliapackages/oracle/src/mappings.ts

mappedrustpackages/oracle/src/mappings.ts

See also: Log2, Log, Log10