Difference between revisions of "Documentation/How Tos/Calc: BETADIST function"
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|<tt>'''BETADIST(1;1;0.5;0;1;FALSE())</tt> | |<tt>'''BETADIST(1;1;0.5;0;1;FALSE())</tt> | ||
| − | : returns '' | + | : returns ''Invalid argument'' because there is a pole |
<tt>'''BETADIST(1.1;1;0.5;0;1;FALSE())</tt> | <tt>'''BETADIST(1.1;1;0.5;0;1;FALSE())</tt> | ||
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| − | |<tt>'''BETADIST()</tt> | + | |<tt>'''BETADIST(1;5;3;-2;4;TRUE())</tt> |
| + | : returns approximately 0.227 | ||
| + | call before version 3.1: <tt>'''BETADIST(1;5;3;-2;4)</tt> | ||
|[[Image:BetaDistributionCumulativeLocationScale.png|Graphs of Beta distribution cumulative functions using parameter a and b]] | |[[Image:BetaDistributionCumulativeLocationScale.png|Graphs of Beta distribution cumulative functions using parameter a and b]] | ||
|} | |} | ||
{| | {| | ||
| − | |<tt>'''BETADIST()</tt> | + | |<tt>'''BETADIST(0.2;0.7;4;0;1;TRUE())</tt> |
| + | : returns approximately 0.718 | ||
| + | call before version 3.1: <tt>'''BETADIST(0.2;0.7:4;0;1)</tt> | ||
| + | |||
| + | other valid call: <tt>'''BETADIST(0.2;0.7;4)</tt> | ||
|[[Image:BetaDistributionCumulativeNormal.png|Graphs of Beta distribution cumulative functions with borders 0 and 1]] | |[[Image:BetaDistributionCumulativeNormal.png|Graphs of Beta distribution cumulative functions with borders 0 and 1]] | ||
|} | |} | ||
{| | {| | ||
| − | |<tt>'''BETADIST()</tt> | + | |<tt>'''BETADIST(1.1;1;0.5;0;1;TRUE())</tt> |
| + | : returns 1 | ||
| + | before version 3.1: <tt>'''BETADIST(1.1;1;0.5;0;1)</tt> | ||
| + | : returns ''Invalid argument'' | ||
|[[Image:BetaDistributionCumulativeSpecial.png|Graphs of Beta distribution cumulative functions with alpha=1]] | |[[Image:BetaDistributionCumulativeSpecial.png|Graphs of Beta distribution cumulative functions with alpha=1]] | ||
|} | |} | ||
Revision as of 20:19, 6 December 2008
BETADIST
Calculates the cumulative distribution function or the probability density function of a beta distribution.
Syntax
BETADIST(x; α; β; a; b; cumulative)
The beta distribution is a family of continuous probability distributions, where α and β are parameters controlling the shape of the distribution.
The parameters a and b are lower and upper bounds of the distribution. You can interpret the value a as location and the value b−a as scale.
a and b are optional parameters which default (if omitted) to 0 and 1.
cumulative is an optional parameter which defaults to TRUE() if omitted.
Before OOo version 3.1 the parameter cumulative doesn't exist and only the cumulative probability function is calculated.
Constraints:
- α > 0 , β > 0 , a < b
- If α < 1, than the density function has a pole at x = a.
- If β < 1, than the density function has a pole at x = b.
Semantic
For cumulative = FALSE() the function BETADIST calculates the probability density function (besides the constraints given above):
For cumulative = TRUE() the function BETADIST calculates the cumulative distribution function:
Notice, that
where
and 
is the regularized incomplete Beta function.
Example
BETADIST(1;5;3;-2;4;FALSE())
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BETADIST(0.2;0.7;4;0;1;FALSE())
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BETADIST(1;1;0.5;0;1;FALSE())
BETADIST(1.1;1;0.5;0;1;FALSE())
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BETADIST(1;5;3;-2;4;TRUE())
call before version 3.1: BETADIST(1;5;3;-2;4) |
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BETADIST(0.2;0.7;4;0;1;TRUE())
call before version 3.1: BETADIST(0.2;0.7:4;0;1) other valid call: BETADIST(0.2;0.7;4) |
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BETADIST(1.1;1;0.5;0;1;TRUE())
before version 3.1: BETADIST(1.1;1;0.5;0;1)
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See also
Functions listed alphabetically, Functions listed by category
