Difference between revisions of "Documentation/How Tos/Calc: DVARP function"
Javier Lopez (Talk | contribs) (Blanked the page) |
Javier Lopez (Talk | contribs) (Undo revision 219933 by Javier Lopez (talk)) |
||
Line 1: | Line 1: | ||
+ | {{Documentation/MasterTOC | ||
+ | |bookid=1234''' | ||
+ | |booktitle=<div style="padding: 8px; font-size: 140%; font-weight: bold; background-color: #9BC0F5;">CALC FUNCTIONS</div> | ||
+ | |ShowParttitle=block|parttitle=[[Documentation/How_Tos/Calc:_Database_functions|<div style="font-size: 140%;">Database Functions]] | ||
+ | |ShowNextPage=block|NextPage= Documentation/How_Tos/Calc:_Date_%26_Time_functions | ||
+ | |ShowPrevPage=block|PrevPage= Documentation/How_Tos/Calc:_DVAR_function | ||
+ | |ShowPrevPart=block|PrevPart= Documentation/How_Tos/Calc:_Complex_Number_functions | ||
+ | |ShowNextPart=block|NextPart= Documentation/How_Tos/Calc:_Date_%26_Time_functions | ||
+ | |toccontent= <div style="padding: 4px; font-size: 130%; font-weight: hidden; background-color:#DCE9FC;">FUNCTIONS</div> | ||
+ | * [[Documentation/How_Tos/Calc:_DCOUNT_function|<div style="font-size: 120%;">Dcount]] | ||
+ | * [[Documentation/How_Tos/Calc:_DCOUNTA_function|<div style="font-size: 120%;">Dcounta]] | ||
+ | * [[Documentation/How_Tos/Calc:_DGET_function|<div style="font-size: 120%;">Dget]] | ||
+ | * [[Documentation/How_Tos/Calc:_DMAX_function|<div style="font-size: 120%;">Dmax]] | ||
+ | * [[Documentation/How_Tos/Calc:_DMIN_function|<div style="font-size: 120%;">Dmin]] | ||
+ | * [[Documentation/How_Tos/Calc:_DAVERAGE_function|<div style="font-size: 120%;">Daverage]] | ||
+ | * [[Documentation/How_Tos/Calc:_DPRODUCT_function|<div style="font-size: 120%;">Dproduct]] | ||
+ | * [[Documentation/How_Tos/Calc:_DSTDEV_function|<div style="font-size: 120%;">Dstdev]] | ||
+ | * [[Documentation/How_Tos/Calc:_DSUM_function|<div style="font-size: 120%;">Dsum]] | ||
+ | * [[Documentation/How_Tos/Calc:_DVAR_function|<div style="font-size: 120%;">Dvar]] | ||
+ | * [[Documentation/How_Tos/Calc:_DVARP_function|<div style="font-size: 120%; border-style: double; border-color:#778899;">Dvarp]] | ||
+ | }}__TOC__ | ||
+ | == DVARP == | ||
+ | Returns the population variance of values in a column of a Calc 'database' table, in rows which meet specified criteria. | ||
+ | |||
+ | |||
+ | === Syntax: === | ||
+ | <tt>'''DVARP(database_table; field; criteria_table)'''</tt> | ||
+ | |||
+ | where | ||
+ | |||
+ | :<tt>'''database_table'''</tt> is a range defining the data to be examined. | ||
+ | |||
+ | :<tt>'''field'''</tt> 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. | ||
+ | |||
+ | :<tt>'''criteria_table'''</tt> is a range containing criteria, which are used to select which rows of the <tt>'''database_table'''</tt> to examine. | ||
+ | |||
+ | |||
+ | :The [[Documentation/How_Tos/Calc: Database functions|Database functions overview]] describes these parameters in detail. | ||
+ | |||
+ | |||
+ | <tt>'''DVARP'''</tt> returns the '''population variance''', which assumes that the chosen rows of the <tt>'''database_table'''</tt> are an entire normally distributed population. If the chosen data are a sample of the population, use '''<tt>* [[Documentation/How_Tos/Calc: DVARP function|DVARP]]</tt>''' instead. The <tt>'''DVARP'''</tt> calculation uses this formula: | ||
+ | |||
+ | <center>[[Image:Calc_pop_var_formula.png]]</center> | ||
+ | |||
+ | where N is the number of values included and x<sub>i</sub> are those values. | ||
+ | |||
+ | |||
+ | <tt>'''DVARP'''</tt> ignores any cell containing text in the <tt>'''field'''</tt> column. | ||
+ | |||
+ | |||
+ | Simply put, variance is a measure of how widely spread data values are. It is the square of the <i>standard deviation</i> (see '''<tt>* [[Documentation/How_Tos/Calc: DSTDEV function|DSTDEV]]</tt>''', '''<tt>* [[Documentation/How_Tos/Calc: DSTDEVP function|DSTDEVP]]</tt>'''). Variance is a reliable measure only if there is enough data to examine. | ||
+ | |||
+ | |||
+ | === Example: === | ||
+ | |||
+ | In this spreadsheet: | ||
+ | |||
+ | {| border="1" | ||
+ | |-align="center" | ||
+ | | ||'''A'''||'''B'''||'''C'''||'''D'''||'''E''' | ||
+ | |||
+ | |-align="center" | ||
+ | |'''1'''||Name||Grade||Age||Distance to School||Weight | ||
+ | |||
+ | |-align="center" | ||
+ | |'''2'''||Andy||3||9||150||40 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''3'''||Betty||4||10||1000||42 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''4'''||Charles||3||10||300||51 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''5'''||Daniel||5||11||1200||48 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''6'''||Eva||2||8||650||33 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''7'''||Frank||2||7||300||42 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''8'''||Greta||1||7||200||36 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''9'''||Harry||3||9||1200||44 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''10'''||Irene||2||8||1000||42 | ||
+ | |||
+ | |-align="center" | ||
+ | |'''11'''|| || || || || | ||
+ | |||
+ | |-align="center" | ||
+ | |'''12'''|| || || || || | ||
+ | |||
+ | |-align="center" | ||
+ | |'''13'''||Name||Grade||Age||Distance to School||Weight | ||
+ | |||
+ | |-align="center" | ||
+ | |'''14'''|| ||2|| || || | ||
+ | |||
+ | |} | ||
+ | |||
+ | |||
+ | <tt>'''DVARP(A1:E10; "Weight"; A13:E14)'''</tt> | ||
+ | |||
+ | : returns the population variance of the weights of children in the second grade. This is not a useful measure, as there are so few children. | ||
+ | |||
+ | ===Issues:=== | ||
+ | * The OOo2.3 Help implies that <tt>'''0'''</tt> as a <tt>'''field'''</tt> will include the entire database table. This seems to be wrong - only the variance 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. | ||
+ | |||
+ | |||
+ | |||
+ | {{Documentation/SeeAlso| | ||
+ | * [[Documentation/How_Tos/Calc: DCOUNT function|DCOUNT]] | ||
+ | * [[Documentation/How_Tos/Calc: DCOUNTA function|DCOUNTA]] | ||
+ | * [[Documentation/How_Tos/Calc: DSUM function|DSUM]] | ||
+ | * [[Documentation/How_Tos/Calc: DPRODUCT function|DPRODUCT]] | ||
+ | * [[Documentation/How_Tos/Calc: DMAX function|DMAX]] | ||
+ | * [[Documentation/How_Tos/Calc: DMIN function|DMIN]] | ||
+ | * [[Documentation/How_Tos/Calc: DAVERAGE function|DAVERAGE]] | ||
+ | * [[Documentation/How_Tos/Calc: DSTDEV function|DSTDEV]] | ||
+ | * [[Documentation/How_Tos/Calc: DSTDEVP function|DSTDEVP]] | ||
+ | * [[Documentation/How_Tos/Calc: DVAR function|DVAR]] | ||
+ | * [[Documentation/How_Tos/Calc: DGET function|DGET]] | ||
+ | * [[Documentation/How_Tos/Calc: VAR function|VAR]] | ||
+ | * [[Documentation/How_Tos/Calc: VARP function|VARP]] | ||
+ | * [[Documentation/How_Tos/Calc: Database functions#Overview|Database functions overview]] | ||
+ | * [[Documentation/How_Tos/Calc: Database functions|Database functions]] | ||
+ | * [[Documentation/How_Tos/Calc: Functions listed alphabetically|Functions listed alphabetically]] | ||
+ | * [[Documentation/How_Tos/Calc: Functions listed by category|Functions listed by category]]}} | ||
+ | [[Category: Documentation/Reference/Calc/Database functions]] |
Revision as of 04:10, 9 May 2013
- Database Functions
- DcountDcountaDgetDmaxDminDaverageDproductDstdev
Contents
DVARP
Returns the population variance of values in a column of a Calc 'database' table, in rows which meet specified criteria.
Syntax:
DVARP(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.
DVARP returns the population variance, 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 * DVARP instead. The DVARP calculation uses this formula:where N is the number of values included and xi are those values.
DVARP ignores any cell containing text in the field column.
Simply put, variance is a measure of how widely spread data values are. It is the square of the standard deviation (see * DSTDEV, * DSTDEVP). Variance 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
DVARP(A1:E10; "Weight"; A13:E14)- returns the population variance of the weights of 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 variance 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.
Template:Documentation/SeeAlso
-