Documentation/How Tos/Calc: DSTDEVP function
Returns the standard deviation of values in a column of a Calc 'database' table, in rows which meet specified criteria.
DSTDEVP(database_table; field; criteria_table)
- 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.
In this spreadsheet:
|1||Name||Grade||Age||Distance to School||Weight|
|13||Name||Grade||Age||Distance to School||Weight|
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.
- 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.