Documentation/Calc Functions/DVAR

TDF LibreOffice Document Liberation Project Community Blogs Weblate Nextcloud Redmine Ask LibreOffice Donate

Other languages:

Calc Functions Home | List of functions | Abbreviations

Function name:

DVAR

Category:

Database

Summary:

This is one of the functions in the Database category that helps you analyze a simple database occupying a rectangular spreadsheet area comprising columns and rows, with the data organized as one row for each record. The header cell of each column displays the name of the column and that name usually reflects the contents of each cell in that column.

DVAR calculates the sample variance based on the numeric values in the cells (fields) of the specified column, for all rows (database records) that match the specified search criteria. Non-numeric values are ignored.

Syntax:

DVAR(Database; DatabaseField; SearchCriteria)

Returns:

Returns a non-negative real number that is the sample variance of the extracted numeric values.

Returns a #NUM! error if exactly one record matches the specified search criteria, or if there is only one numeric value in the cells of the specified column for the matching records.

Returns 0 if no matches are found, or if there are no numeric values in the cells of the specified column for the matching records.

Arguments:

Overview of arguments

All functions in the Database category take three arguments as follows:

Database. The cell range of the database.
DatabaseField. The column containing the data to be used in the function’s calculations.
SearchCriteria. The cell range of a separate area of the spreadsheet containing search criteria.

These arguments are described in more detail in the subsequent sub-sections.

Database argument

Database specifies the range of cells occupied by the database table. The first row of the range contains the field names, and subsequent rows are records with corresponding field values.

One way of defining the range of cells is to enter the cell reference for the upper left-hand cell, followed by a colon (:), and then the lower right-hand cell reference. An example might be A1:E10.
The Database argument may also be specified by passing the name of a named range or database range. Using a meaningful name to define the cell range can enhance formula readability and document maintenance. If the name does not match the name of a defined range, Calc reports a #NAME? error.
Other errors that might be reported as a result of an invalid Database argument are #VALUE! and Err:504 (error in parameter list).

DatabaseField argument

DatabaseField specifies the column which the function will use for its calculations after the search criteria have been applied and the data rows have been selected. It is not related to the search criteria.

Specify the DatabaseField argument in any of the following ways:

By entering a reference to a header cell within the Database area. Alternatively, if the cell has been given a meaningful name as a named range or database range, enter that name. If the name does not match the name of a defined range, Calc reports a #NAME? error. If the name is valid but does not correspond to one cell only, Calc reports Err:504 (error in parameter list).
By entering a number to specify the column within the Database area, starting with 1. For example, if a Database occupied the cell range D6:H123, then enter 3 to indicate the header cell at F6. Calc expects an integer value that lies between 1 and the number of columns defined within Database and ignores any digits after a decimal separator. If the value is less than 1, Calc reports Err:504 (error in parameter list). If the value is greater than the number of columns in Database, Calc reports a #VALUE! error.
By entering the literal column header name from the first row of the Database range, placing quotation marks around the header name; for example, "Distance to School". If the string does not match one of the Database area's column headings, Calc reports Err:504 (error in parameter list). You can also provide a reference to an arbitrary cell (not within the Database and SearchCriteria areas) that contains the required string.

The DatabaseField argument is optional for the DCOUNT and DCOUNTA functions but it is required for the other Database functions.

SearchCriteria argument

SearchCriteria specifies the range of cells containing search criteria. Like Database, its first row is also field names, and subsequent rows are conditions for related fields. The Database and SearchCriteria areas need not be adjacent, or even on the same sheet.

One way of defining the range of cells is to enter the cell reference for the upper left-hand cell, followed by a colon (:), and then the lower right-hand cell reference; for example, A13:B14. The cell range may also be specified by passing the name of a defined named range or database range. If the name does not match the name of a defined range, Calc reports a #NAME? error.
Err:504 (error in parameter list) may also be reported as a result of an invalid SearchCriteria argument.
The contents of the SearchCriteria area are described in more detail in the "Additional details:" section below.

If no matches are found for the given SearchCriteria, or if there are no non-zero numeric values in the cells of the specified column for the matching records of the Database, then the function returns 0.
If exactly one record matches the specified search criteria, or if there is only one numeric value in the cells of the specified column for the matching records, then the function returns a numeric(#NUM!) error.

Additional details:

Outline concept of operation

All functions in the Database category have the same outline concept of operation. The first logical step is to use the specified SearchCriteria to identify the subset of records in the Database that are to be used during subsequent calculations. The second step is to extract the data values and perform the calculations associated with the specific function (average, sum, product, and so on). The values processed are those in the DatabaseField column of the selected records.
The Database category of functions in Calc is sometimes confused with a database managed using LibreOffice Base. However, there is no connection between a database in Base and Calc's Database functions.

Defining search criteria

The number of columns occupied by the SearchCriteria area need not be the same as the width of the Database area. All headings that appear in the first row of SearchCriteria must be identical to headings in the first row of Database. However, not all headings in Database need appear in the first row of SearchCriteria, while a heading in Database can appear multiple times in the first row of SearchCriteria.
Search criteria are entered into the cells of the second and subsequent rows of the SearchCriteria area, below the row containing headings. Blank cells within the SearchCriteria area are ignored.
Create criteria in the cells of the SearchCriteria area using the comparison operators ("<, <=, =, <>, >=, >"). The "=" operator is assumed if a cell is not empty but does not start with a comparison operator.
If you write several criteria in one row, they are connected by AND. If you write several criteria in different rows, they are connected by OR.
Criteria can be created using wildcards, providing that wildcards have been enabled via the Enable wildcards in formulas option on the Tools ▸ Options ▸ LibreOffice Calc ▸ Calculate dialog (LibreOffice ▸ Preferences ▸ LibreOffice Calc ▸ Calculate on macOS). When interoperability with Microsoft Excel is important for your spreadsheet, this option should be enabled.
Even more powerful criteria can be created using regular expressions, providing that regular expressions have been enabled via the Enable regular expressions in formulas option on the Tools ▸ Options ▸ LibreOffice Calc ▸ Calculate dialog.

Note:
When using functions where one or more arguments are search criteria strings that represents a regular expression, the first attempt is to convert the string criteria to numbers. For example, ".0" will convert to "0.0" and so on. If successful, the match will not be a regular expression match but a numeric match. However, switching to a locale where the decimal separator is not the dot makes the regular expression conversion work. To force the evaluation of the regular expression instead of a numeric expression, use some expression that can not be misread as numeric, such as ".[0]" or ".\0" or "(?i).0".

Another setting that affects how the search criteria are handled is the Search criteria = and <> must apply to whole cells option on the Tools ▸ Options ▸ LibreOffice Calc ▸ Calculate dialog. This option controls whether the search criteria you set for the Database functions must match the whole cell exactly. When interoperability with Microsoft Excel is important for your spreadsheet, this option should be enabled.
Many more examples of these search criteria can be found in this Calc spreadsheet.

Dates and logical values

Dates and logical values (TRUE and FALSE) are treated as numeric when calculating with the Database fuctions.

Formula

The formula for the sample variance is:

[math]\displaystyle{ \text{var}~=~\frac{1}{n-1}\sum_{i=1}^{n}\left (x_{i}-\bar{x} \right )^2 }[/math]

where var is the variance, x_i is the value of the i-th sample, n is the count of samples, and x̄ is the mean value.

Examples:

The following database table occupies cells A1:E10 of an otherwise empty sheet and lists imagined information about the guests invited to Joe's birthday party. For each guest, the table lists their name, school grade, age (in years), distance to school (in meters), and weight (in kilograms).

	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

The content of cells A12:E12 should be identical to the header labels for the database table in cells A1:E1. Make sure that cells A13:E13 are blank, except for cell D13 which should contain ">0" (this search criterion is intended to match all records in the database table).

Formula	Description	Returns
=DVAR(A1:E10; "Distance to School"; A12:E13)	Enter this formula into an empty cell elsewhere in the sheet to calculate the sample variance of the distances in meters that Joe’s party guests travel to school.	193125

Many more examples of both search criteria and function calls can be found in this Calc spreadsheet.