From 48c6b57060da96cddab9c82d832dbb8c08c4a317 Mon Sep 17 00:00:00 2001 From: Harrison Booth <73434116+Harrison-Booth@users.noreply.github.com> Date: Fri, 30 Oct 2026 19:34:59 -0500 Subject: [PATCH] G714: return zero Weibull density at zero --- crates/functions/src/stat/distributions.rs | 3 +++ crates/functions/src/stat/tests.rs | 11 +++++++++++ docs/function-parity.md | 3 ++- 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/crates/functions/src/stat/distributions.rs b/crates/functions/src/stat/distributions.rs index cb2f0398a..c67917c36 100644 --- a/crates/functions/src/stat/distributions.rs +++ b/crates/functions/src/stat/distributions.rs @@ -605,6 +605,9 @@ pub(super) fn weibull_dist(a: &[Arg], _: C) -> R { if x < 0.0 || al <= 0.0 || be <= 0.0 { return Err(CellError::Num); } + if x == 0.0 { + return num_val(0.0); + } let t = (x / be).powf(al); num_val(if cum { -(-t).exp_m1() } else { al / be.powf(al) * x.powf(al - 1.0) * (-t).exp() }) } diff --git a/crates/functions/src/stat/tests.rs b/crates/functions/src/stat/tests.rs index 87ce19fac..a00318bd2 100644 --- a/crates/functions/src/stat/tests.rs +++ b/crates/functions/src/stat/tests.rs @@ -479,6 +479,17 @@ fn continuous() { close_tol(r[0][1].clone(), 0.841344746, 1e-8); } +#[test] +fn weibull_density_at_zero_is_zero() { + for shape in [0.5, 1.0, 2.0] { + close_tol(ev("WEIBULL.DIST", vec![n(0.0), n(shape), n(1.0), b(false)]), 0.0, 0.0); + close_tol(ev("WEIBULL.DIST", vec![n(0.0), n(shape), n(1.0), b(true)]), 0.0, 0.0); + } + close_tol(ev("WEIBULL.DIST", vec![n(1.0), n(1.0), n(1.0), b(false)]), (-1.0f64).exp(), 1e-15); + close_tol(ev("WEIBULL.DIST", vec![n(1.0), n(1.0), n(1.0), b(true)]), 1.0 - (-1.0f64).exp(), 1e-15); + is_err(ev("WEIBULL.DIST", vec![n(-0.1), n(1.0), n(1.0), b(false)]), CellError::Num); +} + #[test] fn aggregate_helper() { let vals = vec![nv(1.0), nv(2.0), tv("x"), Value::Empty, Value::Bool(true), nv(6.0)]; diff --git a/docs/function-parity.md b/docs/function-parity.md index bf57fcd3e..fbc83f870 100644 --- a/docs/function-parity.md +++ b/docs/function-parity.md @@ -1,6 +1,6 @@ # Function parity: worksheet functions and formulas -> **Last reviewed:** 2026-10-15 · **Last updated:** 2026-10-25 · **Change:** minor (the LAMBDA row lists the recursion limit and its `#NUM!`, and the error a defined name holding an error gives when called; earlier: number text with accounting parentheses coerces like Excel 365; INDEX with one index on a 2-D reference is #REF! as in Excel; earlier: SUBTOTAL and AGGREGATE cap the cells they visit, #2175) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4 +> **Last reviewed:** 2026-10-31 · **Last updated:** 2026-10-31 · **Change:** minor (WEIBULL.DIST density is zero at x=0, including shape below one, as in Excel; earlier: the LAMBDA row lists the recursion limit and its `#NUM!`, and the error a defined name holding an error gives when called; earlier: number text with accounting parentheses coerces like Excel 365; INDEX with one index on a 2-D reference is #REF! as in Excel; earlier: SUBTOTAL and AGGREGATE cap the cells they visit, #2175) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4 Excel's worksheet functions, category by category, against GridCraft's function library. Part of [target-app-parity.md](target-app-parity.md); gaps feed [gaps.md](gaps.md). @@ -123,6 +123,7 @@ workbooks; results checked in as data, not Excel files) and fixing what it finds | Date | Change | Summary | |---|---|---| +| 2026-10-31 | minor | WEIBULL.DIST returns zero at x=0 in both density and cumulative modes, including shape below one; negative x remains `#NUM!` | | 2026-10-25 | minor | LAMBDA row: a LAMBDA that calls itself more than 140 times, and a formula nested past the depth limit, give `#NUM!` (#1809; nesting gave `#CALC!` before). `=Foo(1)` where the defined name Foo holds `#N/A` gives `#N/A`, not `#NAME?` | | 2026-10-23 | minor | Number text coercion (VALUE, arithmetic, typed entry): a dollar sign before accounting parentheses (`$(1,234)`, `$ (5)`) and a percent sign after them (`(5)%`) read as negatives; `(-5)`, `((5))`, `($-5)`, `$5%`, `$(5)%` and dates or times in parentheses are `#VALUE!`, as observed in Excel 365 | | 2026-10-23 | minor | INDEX with only a row index on a reference of several rows and columns (`INDEX(A1:C3,2)`, `INDEX(A1:C3,0)`) is `#REF!`, as observed in Excel, so it also fails as a range endpoint and inside other functions; an empty column argument (`INDEX(A1:C3,2,)`) still gives the row. Checked that a column array with one index stays a 1×1 array (`TYPE` 64), which is what Excel returns |