FDIST Function (Calligra Sheets)

• Introduced: First release not established; the name is present in Calligra 2.4.0 source.
• Supported in: Calligra Sheets 26.08.2, with no retirement established.
• Scope: Desktop Sheets with the Statistical module. Examples use English semicolon-separated formulas.
• Checked: October 14, 2026. Selected formulas ran through the official 25.04.2 engine library. Source and independent mathematics were checked. This is engine evidence, with no GUI-cell or import verification; 26.08.2 was source-checked only.

FDIST returns P(F≤x) by default. With its optional fourth argument set to zero, it returns an F density. The two degrees of freedom identify the numerator and denominator distributions and remain in that order. Function help.

=FDIST(x;numeratorDF;denominatorDF[;cumulative])

Three arguments are required; cumulative defaults to TRUE. Use x≥0 and degrees of freedom at least 1 and below 10^10. The source does not truncate fractional degrees of freedom. It converts the optional flag to an integer: the tested 0.9 selects density, so explicit TRUE/FALSE is clearer. Brackets indicate optional arguments and are not entered in the formula. Registration and implementation.

The engine and mathematical columns are separate. Results are rounded to twelve decimal places, or thirteen significant digits in scientific notation for very small or large values. This is a display choice, not an accuracy guarantee. NaN and infinity are nonfinite outputs; an engine error flag is checked separately from those values.

For numerator and denominator degrees of freedom both equal to 2, the left-tail CDF is x/(1+x). At x=3, the result is 0.75. The corresponding right-tail probability is 0.25, not 0.75.

The density for this special case is 1/(1+x)^2. At x=3 it is 0.0625, which is a density height rather than the probability of exactly 3. A continuous distribution assigns zero probability to one exact point.

The reciprocal relation connects opposite degree orders: F_CDF(x;d1,d2)+F_CDF(1/x;d2,d1)=1 for x>0. The executed composition uses d1=d2=2 and x=3 and returns 1. For unequal degrees, swapping the orders is essential.

For a variance-ratio application, assign numerator and denominator groups before evaluating the statistic. Reordering them after looking at the data changes the tail interpretation. This function evaluates a distribution; it does not choose a hypothesis test or automatically construct a two-sided p-value.

The executed advanced check was:

=FDIST(3;2;2)+FDIST(1/3;2;2)

Its engine result was 1.

At x=0, the density is singular for numerator df below 2, finite at df=2, and zero above 2. The tested cases show positive infinity with a false error flag for df=1, approximately 1 for df=2 and zero for df=3. A nonfinite result is not an ordinary probability. Negative x and invalid degree bounds return errors.

• Function-specific implementation
• Versioned function help
• Beta helper
• Loggamma helper

The statistical module and value-calculation helpers are byte-identical between the inspected 25.04.2 and 26.08.2 sources. That comparison supports the source discussion but does not establish later-version native output, every locale or arbitrary extreme-parameter accuracy.

NORMDIST, SQRT.