# NaN

`NaN` stands for **N**ot **a** **N**umber and indicates that the data is missing.

Observations containing a value of `NaN` are automatically filtered from any analyses if the question they appear in is numeric. That is:

- NaN values have no impact upon analyses based only upon questions of type: Pick One, Pick One – Multi, Pick Any and Pick Any – Grid, except where numeric statistics, such as Average and Average are being displayed using
**Statistics – Right**or**Statistics – Below**. To automatically filter a value of these questions requires selection of the category as**Missing Data**in the Value Attributes dialog box. - When used to construct JavaScript Variables, NaN values are treated as being missing values.
- NaN settings are ignored in Pick Any, Pick Any - Compact and Pick Any - Grid questions and any variables in such questions only have values of 0 and 1.
- NaN values in variables used as weights are given a weight of 0.
- Observations with values of NaN on numeric variables used as filters are excluded from the filter.