## ISNAN Test for Not-a-Numbers

Section: Inspection Functions

### Usage

Returns true for entries of an array that are NaN's (i.e., Not-a-Numbers). The usage isy = isnan(x)

The result is a logical array of the same size as `x`

,
which is true if `x`

is not-a-number, and false otherwise.
Note that for complex data types that
the result is true if either the real or imaginary parts
are NaNs.

### Example

Suppose we have an array of floats with one element that is`nan`

:
--> a = [1.2 3.4 nan 5] a = 1.2000 3.4000 NaN 5.0000 --> isnan(a) ans = 0 0 1 0