mathjs/docs/reference/functions/arg.md

Function arg

Compute the argument of a complex value. For a complex number a + bi, the argument is computed as atan2(b, a).

For matrices, the function is evaluated element wise.

Syntax

math.arg(x)

Parameters

Parameter	Type	Description
x	number | Complex | Array | Matrix	A complex number or array with complex numbers

Returns

Type	Description
number | Array | Matrix	The argument of x

Examples

var a = math.complex(2, 2);
math.arg(a) / math.pi;          // returns number 0.25

var b = math.complex('2 + 3i');
math.arg(b);                    // returns number 0.982793723247329
math.atan2(3, 2);               // returns number 0.982793723247329

See also

re, im, conj, abs