From 6b70e8a9619d7f050cf5796b90b1f3d834bf14c3 Mon Sep 17 00:00:00 2001 From: Jonas Hahnfeld Date: Wed, 21 Oct 2026 14:32:31 +0200 Subject: [PATCH] [RN] Add release notes for new histogram package --- README/ReleaseNotes/v642/index.md | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/README/ReleaseNotes/v642/index.md b/README/ReleaseNotes/v642/index.md index 07c1bd1b6e63f..10de4d1baad18 100644 --- a/README/ReleaseNotes/v642/index.md +++ b/README/ReleaseNotes/v642/index.md @@ -186,6 +186,15 @@ The behavior for one-dimensional histograms is unchanged. Code that relied on the previous 2D/3D output (for example to build per-axis selection efficiency maps) will now obtain different, mathematically consistent values. +### New histogram package + +The new histogram package continues development in the `ROOT::Experimental` namespace. +This release introduces `RHistEngine::SnapshotAtomic` to obtain a consistent copy during concurrent filling. +There is now a class [`ROOT::Experimental::RProfile`](https://root.cern/doc/v642/classROOT_1_1Experimental_1_1RProfile.html) +for (multidimensional) profile histograms. +`RHist` and `RHistEngine` with two or three dimensions can be converted to `TH2` or `TH3`. +More conversion functions will continue to be added in the future (`THn`, `TProfile`). + ## Math ### Skipping identically-vanishing second derivatives in numerical Hessian evaluation