# Documentation/How Tos/Calc: DSTDEVP function

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## DSTDEVP

Returns the standard deviation of values in a column of a Calc 'database' table, in rows which meet specified criteria.

### Syntax:

DSTDEVP(database_table; field; criteria_table)

where

database_table is a range defining the data to be examined.
field is the column to examine. It may be a column number (1 is the first column of the database table, 2 is the second ...) or a column header (enclosed in quotation marks ””) or a cell referring to a column header.
criteria_table is a range containing criteria, which are used to select which rows of the database_table to examine.

The Database functions overview describes these parameters in detail.

DSTDEVP returns the standard deviation of a population, which assumes that the chosen rows of the database_table are an entire normally distributed population. If the chosen data are a sample of the population, use * DESVEST instead. The DESVESTP calculation uses this formula:

where N is the number of values included and xi are those values.

DSTDEVP ignores any cell containing text in the field column.

Simply put, standard deviation is a measure of how widely spread data values are. It is the square root of the variance (see * DVAR, * DVARP). Standard deviation is a reliable measure only if there is enough data to examine.

### Example:

In this spreadsheet:

 A B C D E 1 Name Grade Age Distance to School Weight 2 Andy 3 9 150 40 3 Betty 4 10 1000 42 4 Charles 3 10 300 51 5 Daniel 5 11 1200 48 6 Eva 2 8 650 33 7 Frank 2 7 300 42 8 Greta 1 7 200 36 9 Harry 3 9 1200 44 10 Irene 2 8 1000 42 11 12 13 Name Grade Age Distance to School Weight 14 2

DSTDEVP(A1:E10; "Weight"; A13:E14)

returns the standard deviation of the weights of children in the second grade, assuming that these are the only children in the second grade. This is not a useful measure, as there are so few children.

### Issues:

• The OOo2.3 Help implies that 0 as a field will include the entire database table. This seems to be wrong - only the standard deviation of a single column can be found.
• Logical values TRUE and FALSE are interpreted as 1 and 0 in the calculation. This is not compatible with Excel, which ignores logical values. This will very rarely cause difficulty.

See Also