Difference between revisions of "Documentation/How Tos/Calc: CHISQDIST function"
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If you need <tt>CHISQDIST(x;k;TRUE())</tt> with a non integer parameter k, then use <tt>GAMMADIST(x;k/2;2)</tt> instead. | If you need <tt>CHISQDIST(x;k;TRUE())</tt> with a non integer parameter k, then use <tt>GAMMADIST(x;k/2;2)</tt> instead. | ||
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+ | For to get the right tail for large values x, do not calculate 1-CHISQDIST. It is less accurate in those cases than using CHIDIST. <tt>CHISQDIST(x;k;TRUE()) + CHIDIST(x;k) = 1</tt>. | ||
In the density case the internal calculation uses logarithmic- and exponential function, if x >1425 or x · k > 1391000. The results are less accurate in those cases. | In the density case the internal calculation uses logarithmic- and exponential function, if x >1425 or x · k > 1391000. The results are less accurate in those cases. |
Revision as of 23:33, 6 December 2008
This function is not yet implemented but expected for OpenOffice.org version 3.1.
CHISQDIST
Calculates values for a χ2-distribution.
Syntax
CHISQDIST(x; k; Cumulative)
- x is the number, at which you will evaluate the χ2-distribution.
- k sets the degrees of freedom for the χ2-distribution
- Constraint: k must be a positive integer
- Cumulative is a logical value.
- In the case Cumulative=TRUE() the cumulative distribution function is used, in the case Cumulative=FALSE() the probability density function. This parameter is optional. It is set to TRUE() if missing.
Semantic
CHISQDIST(x;k;FALSE()) returns values of the probability density function for the χ2-distribution:
CHISQDIST(x;k;TRUE()) returns the left tail probability for the χ2-distribution:
Example
CHSQDIST(2.7;3;FALSE())
- returns approximately 0.1699395239
CHSQDIST(2.7;3;TRUE())
- returns approximately 0.5597727056
Remarks
If you need CHISQDIST(x;k;TRUE()) with a non integer parameter k, then use GAMMADIST(x;k/2;2) instead.
For to get the right tail for large values x, do not calculate 1-CHISQDIST. It is less accurate in those cases than using CHIDIST. CHISQDIST(x;k;TRUE()) + CHIDIST(x;k) = 1.
In the density case the internal calculation uses logarithmic- and exponential function, if x >1425 or x · k > 1391000. The results are less accurate in those cases.
See also:
CHISQINV, LEGACY.CHIDIST, LEGACY.CHIINV, CHITEST
Functions listed alphabetically, Functions listed by category
Issues:
This function is not available in version 3.0 and earlier.