32- and 64-bit floating point values can have the value "void". These types of void values can represent, for instance, outliers in a data series.

Arithmetical operations, such as addition or multiplication with void values provide a void result.

All comparison operations return FALSE if one of the operands is void. The 'is equal to', 'is greater than or equal to' and 'is less than or equal to' comparison operators, however, return TRUE if both operands are void.

With the Analysis of data sets containing void values, these void values are ignored as much as possible. For example, in the case of the formation of a mean value, these values are not taken into consideration.

Due to their structure, some algorithms have the property of dispersing the void attribute. For example, if you calculate an FFT of a time signal with void values, then the result is practically completely void. You should not apply these types of procedures to data sets with void values.

You can display the value "Invalid" in formulas or when editing data sets via a ?.

You can use Cursors to make the values under the active cursor or the entire range between the cursors void. For example, you can use this option to mark outliers in a measured signal as void.

You can use the SignalCorrection analysis object* to remove void values from data sets or to interpolate them.

The functions SearchVoidValues *, ValuesInInterval * can be used to search for void values in a data set.

* Not available in FlexPro View.