GNU Octave Manual Version 3by John W. Eaton, David Bateman, Søren Hauberg Paperback (6"x9"), 568 pages ISBN 095461206X RRP £24.95 ($39.95) |

### 3.1.2 Missing Data

It is possible to represent missing data explicitly in Octave using
`NA`

(short for “Not Available”). Missing data can only be
represented when data is represented as floating point numbers. In this
case missing data is represented as a special case of the representation
of `NaN`

.

__Built-in Function:__**NA***(*`x`)__Built-in Function:__**NA***(*`n`,`m`)__Built-in Function:__**NA***(*`n`,`m`,`k`, ...)__Built-in Function:__**NA***(...,*`class`)- Return a matrix or N-dimensional array whose elements are all equal to the special constant used to designate missing values.

__Mapping Function:__**isna***(*`x`)- Return 1 for elements of
`x`that are NA (missing) values and zero otherwise. For example,isna ([13, Inf, NA, NaN]) => [ 0, 0, 1, 0 ]

ISBN 095461206X | GNU Octave Manual Version 3 | See the print edition |