# sign

## Purpose

Signum function.

## Synopsis

    Y = sign(X)

## Description

`Y = sign(X)` returns a matrix `Y` the same size as `X`, where each element of `Y` is

- 1 if the element is greater than zero
- 0 if it equals zero
- -1 if it is less than zero
  For nonzero complex `X`, `sign(X) = X./abs(X)`.

  ## See Also

      abs, conj, imag, real

  (c) Copyright 1994 by The MathWorks, Inc.