null

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null

Molecular biology
See Null mutation.

Statistics
Completely absent; a set with no members or of zero magnitude. If a field has a value of null, it means that the value is unknown. A null value is not the same as a value of zero, and the difference can be crucial. For example, when calculating the average value of a field among many records where one row contains a zero, the zero gets factored into the average; if the field has a null value, it does not get factored in to the average.
References in periodicals archive ?
The array factor in this case represents a -35 dB constant SLL with the nulls at specific angles.
Figures 6 and 7 show the recovery of two nulls at angles of [[theta].sub.1] = 19.93[degrees] and [[theta].sub.2] = 34.88[degrees], respectively, for 7th sensor failure and SSF.
Now we check the recovery of three nulls at the required positions.
Finally, we will discuss the challenge with null values when trying to create totals on a report.
When a value isn't entered into a field, it's a null value.
The solution for null values isn't always that easy.
Though, we have achieved better null depth level due to SEF, but the sidelobe levels and positioning of nulls is still an issue to be taken into account, for which we shall use the nature inspired evolutionary computing technique, i.e., GA for controlling sidelobe levels and placing the nulls towards required position.
The second term in (8) is used for jammer suppression and placement of nulls at their original positions after element failure.
The array factor in this case represents a -30 dB constant SLL with the nulls at specific angles.
If you are entering the data for this record and fail to ask the client for the County name they live in the data will then be considered missing and the record will be shown including a null. Once this error is realised however, you can then correct it by consulting the client.
You may also have a case for a null value if you are working in a database and none of its values has a record.
You could use a Null value in this field although it is recommended to use a true value such as "N/A" or "Not Applicable", making information clearer to the user.