{ "category": "Engineering functions", "display_name": "DELTA", "entry_kind": "built_in_function", "eval_api": { "method": "POST", "url": "https://handbook.dnacalc.com/api/eval" }, "function_id": "FUNC.DELTA", "implementation_state": { "answer_bank": { "excel_builds": [ "20430" ], "larger_numeric": 0, "last_bit": 0, "matched": 1088, "other_mismatch": 0, "refused": 4, "rows": 1092, "unread": 0, "worst_ulp": 0 }, "detail": "Of 1,096 recorded answers (1,092 in the answer bank and 4 workbook cells), 4 do not match: 4 are refused.", "dnacalc_commit": "9e1884369a678158dd82d3d74188daf986995e87", "in_catalogue": true, "state": "differs", "state_label": "Known larger differences", "summary": "Refuses 4 of 1,096 recorded calls; the rest match", "workbook_corpus": { "cells": 4, "matched": 4 } }, "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/engineering.rs#L264-L269", "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/ported/delta_fn.rs#L3-L5" ], "repository": "https://github.com/DnaCalc/DnaCalc", "shared_code": [], "source": "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/engineering.rs#L264-L269", "state": "differs", "suite": null, "summary": "Refuses 4 of 1,096 recorded calls; the rest match" } ], "json_url": "https://handbook.dnacalc.com/api/functions/FUNC.DELTA.json", "name": "DELTA", "notes": [ { "basis": "16 recorded DELTA and GESTEP formula readings, 8 readings each with errors and text held in cells, and the ERF companions on the same sheets. GESTEP gave the same pattern as DELTA in every pair.", "documentation": null, "evidence": [ { "commit": "287c5b9a3bec81ea96f12ad485f18a0d4b729063", "locator": "delivered_fn4_scalar_logical_positions_and_error_order", "note": "recorded answers pinned", "path": "apps/dna-onecalc/tests/acceptance.rs", "repository": "DnaCalc" }, { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheets qa001 to qa008, qa013 to qa020, qa109 to qa116", "note": "recorded readings", "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" }, { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": null, "note": "8 recorded readings", "path": "crates/calc-func/tests/captures/fn4_questions/DELTA.reading.json", "repository": "DnaCalc" }, { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": null, "note": "8 recorded readings", "path": "crates/calc-func/tests/captures/fn4_questions/GESTEP.reading.json", "repository": "DnaCalc" } ], "functions": [ "FUNC.DELTA", "FUNC.ERF", "FUNC.GESTEP" ], "inferred": null, "kind": "quirk", "note_id": "FN-DELTA-001", "open": [], "recorded_on": "2026-11-04", "repros": [ { "call": "=DELTA(TRUE,#REF!)", "correct": null, "excel": { "bits": null, "display": "#REF!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa007, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=DELTA(#REF!,TRUE)", "correct": null, "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa008, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=GESTEP(TRUE,#REF!)", "correct": null, "excel": { "bits": null, "display": "#REF!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa019, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=GESTEP(#REF!,TRUE)", "correct": null, "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa020, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=ERF(TRUE,#REF!)", "correct": null, "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa115, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=ERF(#REF!,TRUE)", "correct": null, "excel": { "bits": null, "display": "#REF!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa116, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "DELTA(A1, A2)", "correct": null, "excel": { "bits": null, "display": "#REF!", "kind": "error" }, "input_route": "cell-value2", "inputs": [ { "name": "number1", "value": { "bits": null, "display": "#N/A", "kind": "error" } }, { "name": "number2", "value": { "bits": null, "display": "#REF!", "kind": "error" } } ], "recorded_in": "Excel 16.0.20527.20088, Windows, bitness and CPU not recorded in this reading file", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "fn7-DELTA-argument-order-7", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/DELTA.reading.json", "repository": "DnaCalc" } }, { "call": "=DELTA(B1,0)", "correct": null, "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "TRUE", "kind": "logical" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa003, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=DELTA(B1,0)", "correct": null, "excel": { "bits": "0x3ff0000000000000", "display": "1", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa004, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } } ], "schema": "efh.function-note/v1", "statement": "When both arguments of DELTA or GESTEP are bad, the error comes from the second one: DELTA(TRUE,#REF!) is #REF! and DELTA(#REF!,TRUE) is #VALUE!. With two errors, DELTA gives the second. ERF reads left to right: ERF(TRUE,#REF!) is #VALUE! and ERF(#REF!,TRUE) is #REF!. A logical is rejected in either position of these functions, whether typed or held in a cell: DELTA(TRUE,0) and DELTA(2,TRUE) are #VALUE!, and DELTA(B1,0) with TRUE in B1 is #VALUE!, while an empty B1 reads as 0 and gives 1.", "status": "measured", "title": "DELTA and GESTEP read their second argument first" } ], "schema": "efh.function-reference/v1", "section_order": [ "what-it-does", "try-it", "quirks", "how-to-implement", "version-differences", "alternatives" ], "sections": { "alternatives": "\n`--(a=b)` expresses a worksheet equality indicator; [GESTEP](FUNC.GESTEP.md) tests an inclusive threshold; [COUNTIF](FUNC.COUNTIF.md) counts matches over a range.\n\n\n\n\n", "how-to-implement": "\nRead and convert the supplied second scalar first, or use zero when it is omitted. Reject a logical and return an error encountered in that position before reading the first scalar. Then read the first scalar under the same nonlogical numeric rules. A referenced blank is numeric zero.\n\nCompare the admitted numbers for equality and return numeric one or zero, rather than logical TRUE or FALSE. For `(6,6)` the indicator is one. If both inputs are errors, the recorded result is the second error. This read order is part of the implementation; validating left to right changes the answer before the equality test is reached.\n\n\n", "quirks": "\nThe recorded wrapper rejects logicals in either position, including TRUE held in a cell, with `#VALUE!`. A referenced blank instead reads as zero. Errors reveal the read order: `DELTA(TRUE,#REF!)` returns `#REF!`, while `DELTA(#REF!,TRUE)` returns `#VALUE!`, because the second scalar is read first.\n\nEquality applies to the represented inputs, with no tolerance. Mathematically equal decimal expressions can arrive as different binary64 values. A tolerance comparison is a different operation.\n\n\n", "sources": "\n- [FN-DELTA-001](../notes/FN-DELTA-001.json): scalar read order, logical rejection and blank-cell controls.\n- [Microsoft: DELTA function](https://support.microsoft.com/en-us/excel/functions/delta-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/catalogue/engineering.rs); implementation steps and the limits identified in the text.\n\n", "try-it": "\n`=DELTA(6,6)` returns `1`; `=DELTA(6,7)` returns `0`; `=DELTA(0)` returns `1`. Summing such results counts exact matches.\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| 20430 | Windows, 64-bit, CPU not recorded | 1,092 |\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.DELTA.json).", "what-it-does": "\n`DELTA(number1, [number2])` returns numeric one when the two numbers are equal and zero otherwise. The second number defaults to zero. It is an equality indicator, not an approximate-comparison function.\n\n\n" }, "signature": { "display": "DELTA(number1, [number2])", "parameters": [ { "description": null, "name": "number1", "optional": false, "repeats": false }, { "description": null, "name": "number2", "optional": true, "repeats": false } ], "trailing_repeats": false }, "sources": { "metadata": { "admission": { "label": "implemented", "reason": null }, "arity": { "max": 2, "min": 1 }, "category": "Engineering functions", "classification": { "arg_preparation_profile": "ValuesOnlyPreAdapter", "coercion_lift_profile": "Custom", "determinism_class": "Deterministic", "error_collapse_profile": "None", "fec_dependency_profile": "None", "host_interaction_class": "None", "kernel_signature_class": "NumsToNum", "rich_value_usage": "RichBlind", "surface_fec_dependency_profile": "RefOnly", "thread_safety_class": "SafePure", "volatility_class": "NonVolatile" }, "descriptions": { "long": null, "short": "1 when two numbers are equal, otherwise 0", "short_source": "dna-calc-own" }, "docs": { "english_description": "Tests whether two values are equal", "microsoft_url": "https://support.microsoft.com/en-us/office/delta-function-2f763672-c959-4e07-ac33-fe03220ba432" }, "entry_kind": "built_in_function", "localized_family_names": null, "localized_names": [ { "locale": "ar-SA", "name": "DELTA" }, { "locale": "bg-BG", "name": "DELTA" }, { "locale": "cs-CZ", "name": "DELTA" }, { "locale": "da-DK", "name": "DELTA" }, { "locale": "de-DE", "name": "DELTA" }, { "locale": "el-GR", "name": "DELTA" }, { "locale": "en-AU", "name": "DELTA" }, { "locale": "en-GB", "name": "DELTA" }, { "locale": "en-US", "name": "DELTA" }, { "locale": "es-ES", "name": "DELTA" }, { "locale": "et-EE", "name": "DELTA" }, { "locale": "fi-FI", "name": "SAMA.ARVO" }, { "locale": "fr-FR", "name": "DELTA" }, { "locale": "he-IL", "name": "DELTA" }, { "locale": "hr-HR", "name": "DELTA" }, { "locale": "hu-HU", "name": "DELTA" }, { "locale": "id-ID", "name": "DELTA" }, { "locale": "it-IT", "name": "DELTA" }, { "locale": "ja-JP", "name": "差分" }, { "locale": "ko-KR", "name": "델타" }, { "locale": "lt-LT", "name": "DELTA" }, { "locale": "lv-LV", "name": "DELTA" }, { "locale": "nb-NO", "name": "DELTA" }, { "locale": "nl-NL", "name": "DELTA" }, { "locale": "pl-PL", "name": "CZY.RÓWNE" }, { "locale": "pt-BR", "name": "DELTA" }, { "locale": "pt-PT", "name": "DELTA" }, { "locale": "ro-RO", "name": "DELTA" }, { "locale": "ru-RU", "name": "ДЕЛЬТА" }, { "locale": "sk-SK", "name": "DELTA" }, { "locale": "sl-SI", "name": "DELTA" }, { "locale": "sr-Latn-RS", "name": "DELTA" }, { "locale": "sv-SE", "name": "DELTA" }, { "locale": "th-TH", "name": "DELTA" }, { "locale": "tr-TR", "name": "DELTA" }, { "locale": "uk-UA", "name": "DELTA" }, { "locale": "vi-VN", "name": "DELTA" }, { "locale": "zh-CN", "name": "增量" }, { "locale": "zh-HK", "name": "DELTA" }, { "locale": "zh-TW", "name": "DELTA" } ], "signature": { "display": "DELTA(number1, [number2])", "parameters": [ { "description": null, "name": "number1", "optional": false, "repeats": false }, { "description": null, "name": "number2", "optional": true, "repeats": false } ], "trailing_repeats": false }, "surface_name": "DELTA", "version_marker": null, "xlcall": { "code": "418", "symbol": "xlfDelta" } }, "microsoft": "https://support.microsoft.com/en-us/office/delta-function-2f763672-c959-4e07-ac33-fe03220ba432" }, "try_it": { "formula": "=DELTA(6,6)" }, "url": "https://handbook.dnacalc.com/functions/DELTA.html", "variants": [], "versions": [ { "behaviour": "=DELTA(TRUE,#REF!) returned #REF!. =DELTA(#REF!,TRUE) returned #VALUE!. 2 further recorded controls are attached. Inputs were supplied through cells using Value2, formula literals. These are controls from this environment, not a same-input comparison with another build.", "excel_build": "16.0.20527.20088", "observations": [ { "call": "=DELTA(TRUE,#REF!)", "excel": { "bits": null, "display": "#REF!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA" }, { "call": "=DELTA(#REF!,TRUE)", "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "formula-literal", "inputs": [], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA" }, { "call": "=DELTA(B1,0)", "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "TRUE", "kind": "logical" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA" }, { "call": "=DELTA(B1,0)", "excel": { "bits": "0x3ff0000000000000", "display": "1", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA" } ], "platform": "Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/3345a87/content/notes/FN-DELTA-001.json" ] }, { "behaviour": "DELTA(A1, A2) returned #REF!. Inputs were supplied through cells using Value2. These are controls from this environment, not a same-input comparison with another build.", "excel_build": "16.0.20527.20088", "observations": [ { "call": "DELTA(A1, A2)", "excel": { "bits": null, "display": "#REF!", "kind": "error" }, "input_route": "cell-value2", "inputs": [ { "name": "number1", "value": { "bits": null, "display": "#N/A", "kind": "error" } }, { "name": "number2", "value": { "bits": null, "display": "#REF!", "kind": "error" } } ], "recorded_in": "Excel 16.0.20527.20088, Windows, bitness and CPU not recorded in this reading file" } ], "platform": "Windows, bitness and CPU not recorded in this reading file", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/3345a87/content/notes/FN-DELTA-001.json" ] }, { "behaviour": "1,092 captured inputs are indexed for this environment. Capture dates: 2026-09-29 to 2026-09-29. This is a reading count, not a comparison with another build.", "excel_build": "16.0 build 20430", "platform": "Windows, 64-bit, CPU not recorded", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.DELTA.json" ] } ] }