{ "category": "Statistical functions", "display_name": "F.TEST", "entry_kind": "built_in_function", "eval_api": { "method": "POST", "url": "https://handbook.dnacalc.com/api/eval" }, "function_id": "FUNC.F.TEST", "implementation_state": { "answer_bank": { "excel_builds": [ "20131", "20228" ], "larger_numeric": 13, "last_bit": 48, "matched": 17, "other_mismatch": 0, "refused": 0, "rows": 78, "unread": 0, "worst_ulp": 1767616520413419 }, "detail": "Of 84 recorded answers (78 in the answer bank and 6 workbook cells), 61 do not match: 13 differ by more than 16 ULP, 48 differ by at most 16 ULP.", "dnacalc_commit": "9e1884369a678158dd82d3d74188daf986995e87", "in_catalogue": true, "state": "differs", "state_label": "Known larger differences", "summary": "Known larger differences on 61 of 84 recorded answers", "workbook_corpus": { "cells": 6, "matched": 6 } }, "implementations": [ { "commit": "9e1884369a678158dd82d3d74188daf986995e87", "flavour": "excel-compatibility-candidate", "language": "Rust", "name": "CalcFunc", "own_code": [ "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/distributions.rs#L332-L336" ], "repository": "https://github.com/DnaCalc/DnaCalc", "shared_code": [ "catalogue/distributions::sample", "ported/chi_f_t_family::truncate_positive_integer", "ported/chi_f_t_family::validate_nonnegative_x", "ported/chi_f_t_family::f_dist_rt_kernel", "ported/excel_numeric::binary_with", "ported/excel_numeric::excel_x87_add", "ported/excel_numeric::excel_x87_mul", "ported/excel_numeric::excel_x87_mul_add", "ported/excel_numeric/x87::mul", "ported/excel_numeric/x87::add", "ported/special_math_common::bratio_ftoi", "ported/special_math_common::bratio_spmpar1", "ported/special_math_common::bratio_exparg", "ported/special_math_common::bratio_esum", "ported/special_math_common::bratio_esum20", "ported/special_math_common::bratio_alnrel", "ported/special_math_common::bratio_rlog1", "ported/special_math_common::bratio_gam1", "ported/special_math_common::bratio_gamln1", "ported/special_math_common::bratio_gamln", "ported/special_math_common::bratio_algdiv", "ported/special_math_common::bratio_bcorr", "ported/special_math_common::bratio_gsumln", "ported/special_math_common::bratio_betaln", "ported/special_math_common::bratio_betaln_60", "ported/special_math_common::bratio_erf_nswc", "ported/special_math_common::bratio_erfc1", "ported/special_math_common::bratio_rexp", "ported/special_math_common::bratio_psi", "ported/special_math_common::bratio_fpser", "ported/special_math_common::bratio_apser", "ported/special_math_common::bratio_bpser", "ported/special_math_common::bratio_bup", "ported/special_math_common::bratio_brcomp", "ported/special_math_common::bratio_brcmp1", "ported/special_math_common::bratio_bfrac", "ported/special_math_common::bratio_bgrat", "ported/special_math_common::bratio_grat1", "ported/special_math_common::bratio_basym", "ported/special_math_common::bratio", "ported/statistical_tests_family::sample_mean", "ported/statistical_tests_family::sample_variance", "ported/statistical_tests_family::f_test_kernel" ], "source": "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/distributions.rs#L332-L336", "state": "differs", "suite": null, "summary": "Known larger differences on 61 of 84 recorded answers" } ], "json_url": "https://handbook.dnacalc.com/api/functions/FUNC.F.TEST.json", "name": "F.TEST", "notes": [], "schema": "efh.function-reference/v1", "section_order": [ "what-it-does", "try-it", "quirks", "how-to-implement", "version-differences", "alternatives" ], "sections": { "alternatives": "\n[F.DIST.RT](FUNC.F.DIST.RT.md) accepts a supplied ratio; [VAR.S](FUNC.VAR.S.md) reports sample variance; [T.TEST](FUNC.T.TEST.md) compares means under its selected model.\n\n\n", "how-to-implement": "\nCompute each sample variance and its count, put the larger variance in the numerator, and retain its matching degree count `n-1`. Evaluate the F right tail of the ratio, double it and cap at one. For the example both variances are one and both degree counts two. The current helper uses its own centered binary64 sample-variance calculation; it does not automatically inherit the separately recovered VAR.S computation tree. Tail and reduction discrepancies remain recorded.\n\n\n", "quirks": "\nEach sample needs at least two numeric observations and a nonzero variance, otherwise `#DIV/0!`. Text, logical values and blanks in references are ignored; zeros count. Equal sample variances do not imply equal sample means or identical observations.\n\n\n", "sources": "\n- [Microsoft: F.TEST function](https://support.microsoft.com/en-us/excel/functions/f-test-function), opened 6 November 2026; syntax, documented argument rules and errors.\n- [DnaCalc implementation](https://github.com/DnaCalc/DnaCalc/blob/da3ecc4fb19a3a5529708c311d0e8f05688ac165/crates/calc-func/src/ported/statistical_tests_family.rs); implementation steps and the limits identified in the text.\n\n", "try-it": "\n`=F.TEST({1,2,3},{2,3,4})` returns `1` under the current route. Both sample variances are one, so their ratio is one with equal degree counts.\n\n\n", "version-differences": "The recorded environments below distinguish a reading from a same-input comparison. Counts describe captured inputs in each environment; overlapping captures and comparisons are not totals of unique worksheet calls.\n\n| Excel 16.0 build | Platform and CPU | Captured inputs |\n|---|---|---:|\n| 20131 | Windows, bitness not recorded, AMD Ryzen 7 4800H with Radeon Graphics | 3 |\n| 20228 | Windows, 64-bit, CPU not recorded | 75 |\n\nThe record contains no same-input comparison between these environments. Reading different inputs on different builds does not establish either a version change or cross-build agreement.\n\n[Recorded environments and comparison details](https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.F.TEST.json).", "what-it-does": "\n`F.TEST(array1,array2)` returns a two-tailed F-test probability for comparing sample variances. It returns a probability, rather than the variance ratio statistic.\n\n\n" }, "signature": { "display": "F.TEST(array1, array2)", "parameters": [ { "description": null, "name": "array1", "optional": false, "repeats": false }, { "description": null, "name": "array2", "optional": false, "repeats": false } ], "trailing_repeats": false }, "sources": { "metadata": { "admission": { "label": "implemented", "reason": null }, "arity": { "max": 2, "min": 2 }, "category": "Statistical functions", "classification": { "arg_preparation_profile": "RefsVisibleInAdapter", "coercion_lift_profile": "Custom", "determinism_class": "Deterministic", "error_collapse_profile": "None", "fec_dependency_profile": "RefOnly", "host_interaction_class": "None", "kernel_signature_class": "Custom", "rich_value_usage": "RichBlind", "surface_fec_dependency_profile": "RefOnly", "thread_safety_class": "SafePure", "volatility_class": "NonVolatile" }, "descriptions": { "long": null, "short": "Two-tailed probability that two samples' variances do not differ", "short_source": "dna-calc-own" }, "docs": { "english_description": "Returns the result of an F-test", "microsoft_url": "https://support.microsoft.com/en-us/office/f-test-function-100a59e7-4108-46f8-8443-78ffacb6c0a7" }, "entry_kind": "built_in_function", "localized_family_names": null, "localized_names": [ { "locale": "ar-SA", "name": "F.TEST" }, { "locale": "bg-BG", "name": "F.TEST" }, { "locale": "cs-CZ", "name": "F.TEST" }, { "locale": "da-DK", "name": "F.TEST" }, { "locale": "de-DE", "name": "F.TEST" }, { "locale": "el-GR", "name": "F.TEST" }, { "locale": "en-AU", "name": "F.TEST" }, { "locale": "en-GB", "name": "F.TEST" }, { "locale": "en-US", "name": "F.TEST" }, { "locale": "es-ES", "name": "PRUEBA.F.N" }, { "locale": "et-EE", "name": "F.TEST" }, { "locale": "fi-FI", "name": "F.TESTI" }, { "locale": "fr-FR", "name": "F.TEST*" }, { "locale": "he-IL", "name": "F.TEST" }, { "locale": "hr-HR", "name": "F.TEST" }, { "locale": "hu-HU", "name": "F.PRÓB" }, { "locale": "id-ID", "name": "F.TEST" }, { "locale": "it-IT", "name": "F.TEST" }, { "locale": "ja-JP", "name": "F.TEST" }, { "locale": "ko-KR", "name": "F.TEST" }, { "locale": "lt-LT", "name": "F.TEST" }, { "locale": "lv-LV", "name": "F.TEST" }, { "locale": "nb-NO", "name": "F.TEST" }, { "locale": "nl-NL", "name": "F.TEST" }, { "locale": "pl-PL", "name": "F.TEST" }, { "locale": "pt-BR", "name": "F.TEST" }, { "locale": "pt-PT", "name": "TESTE.F" }, { "locale": "ro-RO", "name": "F.TEST" }, { "locale": "ru-RU", "name": "F.ТЕСТ" }, { "locale": "sk-SK", "name": "F.TEST" }, { "locale": "sl-SI", "name": "F.TEST" }, { "locale": "sr-Latn-RS", "name": "F.TEST" }, { "locale": "sv-SE", "name": "F.TEST" }, { "locale": "th-TH", "name": "F.TEST" }, { "locale": "tr-TR", "name": "F.TEST" }, { "locale": "uk-UA", "name": "F.TEST" }, { "locale": "vi-VN", "name": "F.TEST" }, { "locale": "zh-CN", "name": "F.TEST" }, { "locale": "zh-HK", "name": "F.TEST" }, { "locale": "zh-TW", "name": "F.TEST" } ], "signature": { "display": "F.TEST(array1, array2)", "parameters": [ { "description": null, "name": "array1", "optional": false, "repeats": false }, { "description": null, "name": "array2", "optional": false, "repeats": false } ], "trailing_repeats": false }, "surface_name": "F.TEST", "version_marker": null, "xlcall": { "code": "491", "symbol": "xlfF_test" } }, "microsoft": "https://support.microsoft.com/en-us/office/f-test-function-100a59e7-4108-46f8-8443-78ffacb6c0a7" }, "try_it": { "formula": "=F.TEST({1,2,3},{2,3,4})" }, "url": "https://handbook.dnacalc.com/functions/F.TEST.html", "variants": [], "versions": [ { "behaviour": "3 captured inputs are indexed for this environment. Capture dates: 2026-07-12 to 2026-07-12. This is a reading count, not a comparison with another build.", "excel_build": "16.0 build 20131", "platform": "Windows, bitness not recorded, AMD Ryzen 7 4800H with Radeon Graphics", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.F.TEST.json" ] }, { "behaviour": "75 captured inputs are indexed for this environment. Capture dates: 2026-08-09 to 2026-08-09. This is a reading count, not a comparison with another build.", "excel_build": "16.0 build 20228", "platform": "Windows, 64-bit, CPU not recorded", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.F.TEST.json" ] } ] }