Difference between revisions of "Documentation/How Tos/Calc: DSTDEVP function"

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:The '''[[Documentation/How_Tos/Calc: Database functions|Database functions overview]]''' describes these parameters in detail.
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:The * [[Documentation/How_Tos/Calc: Database functions|Database functions overview]]''' describes these parameters in detail.
  
  
<tt>'''DSTDEVP'''</tt> returns the '''standard deviation of a population''', 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: DSTDEV function|DESVEST]]</tt>''' instead. The <tt>'''DESVESTP'''</tt> calculation uses this formula:
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<tt>'''DSTDEVP'''</tt> returns the '''standard deviation of a population''', 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: DSTDEV function|DESVEST]]</tt>''' instead. The <tt>'''DESVESTP'''</tt> calculation uses this formula:
  
 
<center>[[Image:Calc_pop_stddev_formula.png]]</center>
 
<center>[[Image:Calc_pop_stddev_formula.png]]</center>
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Simply put, standard deviation is a measure of how widely spread data values are. It is the square root of the <i>variance</i> (see '''<tt>[[Documentation/How_Tos/Calc: DVAR function|DVAR]]</tt>''', '''<tt>[[Documentation/How_Tos/Calc: DVARP function|DVARP]]</tt>'''). Standard deviation is a reliable measure only if there is enough data to examine.
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Simply put, standard deviation is a measure of how widely spread data values are. It is the square root of the <i>variance</i> (see '''<tt>* [[Documentation/How_Tos/Calc: DVAR function|DVAR]]</tt>''', '''<tt>* [[Documentation/How_Tos/Calc: DVARP function|DVARP]]</tt>'''). Standard deviation is a reliable measure only if there is enough data to examine.
  
 
=== Example: ===
 
=== Example: ===
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{| border="1"  
 
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|-align="center"
 
|-align="center"
|&nbsp;||'''A'''||B'''||C'''||'''D'''||'''E'''
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|&nbsp;||A'''||B'''||C'''||D'''||E'''
  
 
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|-align="center"
|'''1'''||Name||Grade||Age||Distance to School||Weight
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|1'''||Name||Grade||Age||Distance to School||Weight
  
 
|-align="center"
 
|-align="center"
|'''2'''||Andy||3||9||150||40
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|2'''||Andy||3||9||150||40
  
 
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|-align="center"
|'''3'''||Betty||4||10||1000||42
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|3'''||Betty||4||10||1000||42
  
 
|-align="center"
 
|-align="center"
|'''4'''||Charles||3||10||300||51
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|4'''||Charles||3||10||300||51
  
 
|-align="center"
 
|-align="center"
|'''5'''||Daniel||5||11||1200||48
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|5'''||Daniel||5||11||1200||48
  
 
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|'''6'''||Eva||2||8||650||33
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|6'''||Eva||2||8||650||33
  
 
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|'''7'''||Frank||2||7||300||42
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|7'''||Frank||2||7||300||42
  
 
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|'''8'''||Greta||1||7||200||36
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|8'''||Greta||1||7||200||36
  
 
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|'''9'''||Harry||3||9||1200||44
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|9'''||Harry||3||9||1200||44
  
 
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|'''10'''||Irene||2||8||1000||42
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|10'''||Irene||2||8||1000||42
  
 
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|'''11'''||&nbsp;||&nbsp;||&nbsp;||&nbsp;||&nbsp;
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|'''13'''||Name||Grade||Age||Distance to School||Weight
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|13'''||Name||Grade||Age||Distance to School||Weight
  
 
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=== See also: ===
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{{Documentation/SeeAlso|
'''[[Documentation/How_Tos/Calc: DCOUNT function|DCOUNT]]''',
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* [[Documentation/How_Tos/Calc: DCOUNT function|DCOUNT]]
'''[[Documentation/How_Tos/Calc: DCOUNTA function|DCOUNTA]]''',
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* [[Documentation/How_Tos/Calc: DCOUNTA function|DCOUNTA]]
'''[[Documentation/How_Tos/Calc: DSUM function|DSUM]]''',
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* [[Documentation/How_Tos/Calc: DSUM function|DSUM]]
'''[[Documentation/How_Tos/Calc: DPRODUCT function|DPRODUCT]]''',
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* [[Documentation/How_Tos/Calc: DPRODUCT function|DPRODUCT]]
'''[[Documentation/How_Tos/Calc: DMAX function|DMAX]]''',
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* [[Documentation/How_Tos/Calc: DMAX function|DMAX]]
'''[[Documentation/How_Tos/Calc: DMIN function|DMIN]]''',
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* [[Documentation/How_Tos/Calc: DMIN function|DMIN]]
'''[[Documentation/How_Tos/Calc: DAVERAGE function|DAVERAGE]]''',
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* [[Documentation/How_Tos/Calc: DAVERAGE function|DAVERAGE]]
'''[[Documentation/How_Tos/Calc: DSTDEV function|DSTDEV]]''',
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* [[Documentation/How_Tos/Calc: DSTDEV function|DSTDEV]]
'''[[Documentation/How_Tos/Calc: DVAR function|DVAR]]''',
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* [[Documentation/How_Tos/Calc: DVAR function|DVAR]]
'''[[Documentation/How_Tos/Calc: DVARP function|DVARP]]''',
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* [[Documentation/How_Tos/Calc: DVARP function|DVARP]]
'''[[Documentation/How_Tos/Calc: DGET function|DGET]]'''
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* [[Documentation/How_Tos/Calc: DGET function|DGET]]'''
  
'''[[Documentation/How_Tos/Calc: STDEVP function|STDEVP]]'''
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* [[Documentation/How_Tos/Calc: STDEVP function|STDEVP]]'''
  
'''[[Documentation/How_Tos/Calc: Database functions#Overview|Database functions overview]]'''
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* [[Documentation/How_Tos/Calc: Database functions#Overview|Database functions overview]]'''
  
'''[[Documentation/How_Tos/Calc: Database functions|Database functions]]'''
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* [[Documentation/How_Tos/Calc: Database functions|Database functions]]'''
  
[[Documentation/How_Tos/Calc: Functions listed alphabetically|'''Functions listed alphabetically''']],
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* [[Documentation/How_Tos/Calc: Functions listed alphabetically|Functions listed alphabetically]]
[[Documentation/How_Tos/Calc: Functions listed by category|'''Functions listed by category''']]
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* [[Documentation/How_Tos/Calc: Functions listed by category|Functions listed by category]]}}
  
 
==Issues:==
 
==Issues:==

Revision as of 13:45, 25 February 2009


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:

Calc pop stddev formula.png

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.


Template:Documentation/SeeAlso

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.
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