feat(wip): cupy histograms

pyproject.toml

@@ -93,6 +93,10 @@ rucio = [
   "rucio-clients>=32;python_version>'3.8'",
   "rucio-clients<32;python_version<'3.9'",
 ]
+gpu = [
+  "cupy-cuda12x>=13.1.0",
+  "numba-cuda>=0.0.13",
+]
 dev = [
   "pre-commit",
   "flake8",

src/coffea/jitters/hist/__init__.py

@@ -0,0 +1,38 @@
+"""Histogramming tools
+
+`coffea.hist` is a histogram filling, transformation, and plotting sub-package, utilizing
+numpy arrays for storage and matplotlib plotting routines for visualization.
+
+Features found in this package are similar to those found in
+packages such as `histbook <https://github.com/scikit-hep/histbook>`__ (deprecated),
+`boost-histogram <https://github.com/scikit-hep/boost-histogram>`__ (in development),
+`physt <https://github.com/scikit-hep/boost-histogram>`__, and built-in numpy
+`histogram <https://docs.scipy.org/doc/numpy/reference/generated/numpy.histogram.html>`__ utilities.
+
+"""
+
+from coffea.jitters.hist.hist_tools import Bin, Cat, Hist, Interval, StringBin
+from coffea.jitters.hist.plot import (
+    clopper_pearson_interval,
+    normal_interval,
+    plot1d,
+    plot2d,
+    plotgrid,
+    plotratio,
+    poisson_interval,
+)
+
+__all__ = [
+    "Hist",
+    "Bin",
+    "Interval",
+    "Cat",
+    "StringBin",
+    "poisson_interval",
+    "clopper_pearson_interval",
+    "normal_interval",
+    "plot1d",
+    "plotratio",
+    "plot2d",
+    "plotgrid",
+]