SIGN
----

**Purpose**


.. figure:: ../media/image1007.png
   :figwidth: 4.60417in
   :align: center 

**Purpose**

Returns the sign of an input value.

**Procedure** 

At each time step the sign of the input signal is output according to the following scheme:

-  If :math:`x > 0` then output = +1.

-  If :math:`x = 0` then output = 0.

-  If :math:`x < 0` then output = -1.

**Parameters** 

None.

**Remarks** 

None.

**Examples** 

None.

.. include:: substitutions_control.rst