.. highlightlang:: us

.. _isnan:

isnan
=====

.. index:: isnan

.. us.tag  isnan NOTREADYENGLISH

:ref:`isnan` checks if the argument is not a number (NaN). For example 0/0.

.. function::  r = isnan(m)

.. us.return

**Return Value**

*r* is TRUE (1) if *m* is NaN, otherwise it is FALSE (0).

.. us.params

**Parameters**

.. uparam:: m

   *m* is a real scalar or real matrix.

.. us.example

**Example**

::

   1/0
       1.#INF
   0/0
       -1.#IND
   isinf(1/0)
       1.0000
   isinf(0/0)
       1.0000
   isnan(1/0)
       0.0000
   isnan(0/0)
       1.0000
   isnan(0/0)
       1.0000
   isnan(1e300*1e300)
       1.0000
   isnan(-1e300*-1e300)
       1.0000

.. seealso::
   :ref:`overview-mathematic`,
   :ref:`isinf`

:sub:`id-401091`