Section: Base Constants
y = nan
The returned type is a 64-bit float, but demotion to 32 bits preserves the not-a-number. The not-a-number constant has one simple property. In particular, any arithmetic operation with a NaN results in a NaN. These calculations run significantly slower than calculations involving finite quantities! Make sure that you use NaNs in extreme circumstances only. Note that NaN is not preserved under type conversion to integer types (see the examples below).
--> nan*0
ans =
nan
--> nan-nan
ans =
nan
-->
quit
Note that NaNs are preserved under type conversion to floating point types (i.e., float, double, complex and dcomplex types), but not integer types.
--> uint32(nan)
ans =
0
--> complex(nan)
ans =
nan + 0.0000i
-->
quit