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Function
src/index.ts:772nerdamer.log
nerdamer.log(x: ExpressionInput, base?: ExpressionInput, expandPrimes: boolean): ExpressionComputes the natural (base-e) logarithm, or optionally a logarithm with a specified base. When
`Settings.EVALUATE`is
`false`, real-domain logarithm identities are applied only when their arguments are provably positive real values. This keeps product, quotient, and power rewrites from crossing principal complex branches when a symbolic sign is unknown. For known negative real inputs, returns
`log(|x|) + iπ`. Complex inputs use the principal branch:
`log(z) = log|z| + i·arg(z)`.
throws
UndefinedError If
`x`is
`-∞`.
Parameters
| Name | Type | Description |
|---|---|---|
x | ExpressionInput | The expression to take the logarithm of. |
base | ExpressionInput | Optional logarithm base. Defaults to `e` (natural log). |
expandPrimes | boolean | When `true`, decomposes integer arguments into prime factors (e.g. `log(8)` becomes `3·log(2)`). Defaults to `false`. |
Returns
Expression — The logarithm of `x`.
Examples
log('e').text() // "1"
log(1).text() // "0"
log('e^x').text() // "x"
// With base
log(8, 2).text() // "3"