From 717b96c278da54ba199dabaf613d6ec12cadde85 Mon Sep 17 00:00:00 2001
From: dcherian <deepak@cherian.net>
Date: Mon, 27 Mar 2023 10:43:20 -0600
Subject: [PATCH] Use faster group_idx creation when axis == -1

xref https://github.com/xarray-contrib/flox/issues/222
xref #46
xref #51
xref #60
---
 numpy_groupies/utils_numpy.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/numpy_groupies/utils_numpy.py b/numpy_groupies/utils_numpy.py
index cdcd9df..8e3062f 100644
--- a/numpy_groupies/utils_numpy.py
+++ b/numpy_groupies/utils_numpy.py
@@ -277,7 +277,6 @@ def input_validation(
     axis=None,
     ravel_group_idx=True,
     check_bounds=True,
-    method="ravel",
     func=None,
 ):
     """Do some fairly extensive checking of group_idx and a, trying to
@@ -331,6 +330,7 @@ def input_validation(
             else:
                 unravel_shape = None
 
+            method = "offset" if axis == ndim_a - 1 else "ravel"
             group_idx, size = _ravel_group_idx(
                 group_idx, a, axis, size, order, method=method
             )