Function reference · Math

`sign`

Returns the sign of a real expression when it can be determined.

The result is 1, -1, or 0 for known positive, negative, or zero values. Assumptions can resolve symbolic signs; otherwise sign(x) remains symbolic.

Complex inputs are delegated to the complex sign function.

Examples

These examples use Nerdamer Notation.

Identify a positive number.

sign(5)
// → 1

Identify a negative number.

sign(-3)
// → -1

Preserve an unknown sign.

sign(x)

The same operation is available through the interfaces below.

Use this form inside input passed to nerdamer(...).

sign(arg1)

Call the operation through the default nerdamer import.

nerdamer.sign(x: ExpressionInput): Expression

Name	Type	Description
`x`	`ExpressionInput`	The expression whose sign to determine.

Expression — `1`, `-1`, or `0` as an Expression, or a symbolic `sign(x)` node.