TRIMMEAN Function (Gnumeric)

• Introduced: Gnumeric 0.19 release notes record its addition.
• Supported in: Gnumeric 1.12.62; no retirement is established.
• Scope: Desktop Gnumeric with its Statistics plugin. English comma-separated formulas are shown.
• Checked: October 14, 2026. The tables and named advanced check use 1.12.57 ssconvert. Current 1.12.62 source was inspected; that release was not executed.

TRIMMEAN sorts the numeric observations, removes the same number from each end, and averages what remains. Its fraction is the total fraction to remove, not the fraction removed from each tail. The excluded count is rounded down to an even integer. Versioned function help.

=TRIMMEAN(array,fraction)

• array: a list or range of numbers. Text, booleans and blank cells are ignored.
• fraction: a number at least 0 and less than 1. For n retained numbers, the number removed from each end is floor(n*fraction/2).

Current implementation.

Enter these columns as numbers, except for the explicitly typed H column. F7 and H7 are genuinely empty.

Use an apostrophe entry marker if needed to store H5 as text; it is not part of the stored value. The results below are native outputs rounded to 12 decimal places for readability, rather than application screenshots.

With recorded times 1,2,3,4,10 in F2:F6, =TRIMMEAN(F2:F6,0.4) removes 1 and 10 and averages 2,3,4, giving 3. A fraction of 0.2 removes nobody: five times 0.2 is one, and the excluded count rounds down to zero. That result is the ordinary mean 4.

Choose a trimming rule before comparing groups and report it. Trimming changes the summary’s meaning; it does not establish that the removed observations were mistakes.

The mean changes in steps as fraction increases. With five numbers, fractions below 0.4 remove zero values, fractions from 0.4 up to but below 0.8 remove two, and fractions from 0.8 up to 1 remove four. For F2:F6 the results are 4,3,3. With four values 1,2,3,4 and fraction 0.5, the two central values remain, giving 2.5.

The native =TRIMMEAN(F2:F6,0.4) check is 3. Reflecting the values changes the result to −3; adding 100 changes it to 103. The operation discards whole observations rather than replacing extremes with cutoff values.

The relevant argument guards and calculation sequence are preserved in the retained 1.12.57 and 1.12.62 callbacks. This is a source comparison; later-release output was not tested.

Fraction below 0 or at least 1 produces #NUM!. A singleton survives any allowed fraction. An array with no numeric observations produces #VALUE!. Numeric text used as the fraction is parsed in the tested English context; referenced text inside the data is still ignored.

• Current worksheet implementation
• Tested-version worksheet implementation

Both the stale SUM cache and the uncached SUM recalculated correctly. Saved formula identities and typed inputs were checked in the native workbook exports. The importer reported unsupported style-extension elements; this does not establish complete formatting support. GUI entry, other locales and later-version execution were not tested.

AVERAGE, MEDIAN, COUNT.