CHISQDIST Function (OpenOffice Calc)

• Introduced: Added in OpenOffice.org 3.1, whose release notes explicitly introduce this function.
• Supported in: Apache OpenOffice 4.1.16; no final supported release established.
• Scope: Desktop Calc. Argument contracts and boundaries below refer to the cited release.
• Checked: October 14, 2026. Documentation/source and independent mathematics checked; Apache OpenOffice Calc was not run for this guide.

CHISQDIST evaluates the chi-square distribution with the supplied degrees of freedom. Its default cumulative result is P(X≤x). Density mode describes the curve height at x; it is not the probability of one exact continuous outcome. Official reference.

For positive x and degrees of freedom k, the density is x^(k/2−1)×exp(−x/2)/(2^(k/2)×Γ(k/2)). The cumulative value integrates that density from zero to x. This is the gamma model with shape k/2 and scale 2, but the Calc chi-square function handles its integer parameter and endpoint convention explicitly.

=CHISQDIST(Number; Degrees_of_freedom [; Cumulative])

The first two arguments are required. Cumulative is optional: omission or TRUE selects the left-tail probability; FALSE selects density. The release evaluator accepts two or three arguments and floors degrees of freedom before requiring a value of at least 1.

Choose a positive integer degree count from the statistical problem instead of relying on flooring. The function cannot infer whether a goodness-of-fit test, a variance calculation or another model gives the appropriate count.

The table gives independently calculated values, rounded to twelve decimal places. Its zero and negative-x entries follow the explicit Calc boundary convention.

Put 6 in A2, 2 in B2 and 1 in C2. In D2 enter =CHISQDIST(A2;B2;C2). The expected value is 0.950212931632. Changing C2 to 0 gives density 0.024893534184, which must not be interpreted as the cumulative probability.

For a right-tail probability at the same positive statistic, =1-CHISQDIST(A2;B2;1) is approximately 0.049787068368. The complement is convenient at ordinary values; very small upper tails can lose precision when subtracting a value close to 1. A dedicated right-tail function is preferable for such calculations.

For k=2, the probability between 2 and 6 is =CHISQDIST(6;2;1)-CHISQDIST(2;2;1), approximately 0.318092372804. Subtract cumulative probabilities, not densities. Reversing the endpoints creates a negative difference rather than a meaningful interval probability.

The 95th percentile can be found with =CHISQINV(0.95;2), approximately 5.991464547108. Feeding its unrounded result into =CHISQDIST(CHISQINV(0.95;2);2;1) should recover approximately 0.95. The distribution and inverse must use the same degree count.

The CDF and density helpers both return zero for x≤0. In density mode that is a software convention: at k=2 the mathematical right-hand limit at zero is 0.5, and at k=1 the density diverges. Do not replace the documented endpoint result with that limit.

CHIDIST represents a right-tail probability; it is not an alternate spelling for CHISQDIST. Do not import dotted Excel function names or their argument requirements without checking OpenOffice compatibility. Invalid degrees of freedom and an ordinary zero probability are different outcomes. These cases do not establish extreme-tail accuracy or locale-specific coercion behavior.

• CHISQDIST documentation
• Apache OpenOffice 4.1.16 evaluator and argument contract