arg

Arg is a short form that appears in several unrelated fields. In geography and international usage, ARG is the ISO 3166-1 alpha-3 code for Argentina, and it is widely used in sports codes such as the IOC and FIFA, as well as various administrative identifiers. In mathematics and computing, Arg is used to denote an angle or a position in a coordinate system; it is often associated with the argument of a complex number.

In complex analysis, Arg(z) denotes the argument of a complex number z, defined as the angle between the positive real axis and the line representing z in the complex plane. The Argand plane is the two-dimensional representation used for complex numbers, named for Jean-Robert Argand. The principal value of the argument is typically written Arg(z) and is restricted to a chosen interval (for example (-pi, pi]), while arg(z) may denote the multi-valued argument.

In computing, arg is shorthand for argument—the value supplied to a function or program. In many languages, command-line arguments are stored in structures such as argc and argv; a single argument is one element of argv.

As a general term, arg can be an informal abbreviation for argument in rhetoric or logic, referring to a claim or set of reasons offered in support of a conclusion.