From 41074ae9df5e0f8eedd5064a9274f6fc3b9633a3 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Thu, 22 Feb 2018 14:39:52 -0600
Subject: [PATCH 1/3] Improve max-level error message (Closes #22)

---
 boxtree/tree_build.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/boxtree/tree_build.py b/boxtree/tree_build.py
index 2566dc4..42bc3bd 100644
--- a/boxtree/tree_build.py
+++ b/boxtree/tree_build.py
@@ -540,8 +540,12 @@ class TreeBuilder(object):
                 assert level == len(level_used_box_counts)
                 assert level == len(level_leaf_counts)
 
-            if level > np.iinfo(self.box_level_dtype).max:
-                raise RuntimeError("level count exceeded maximum")
+            assert np.iinfo(self.box_level_dtype).max >= np.finfo(coord_dtype).mnant
+            if level > np.finfo(coord_dtype).nmant:
+                raise RuntimeError("Level count exceeded number of significant "
+                        "bits in coordinate dtype. That means that a large number "
+                        "of particles was indistinguishable up to floating point "
+                        "precision (because they ended up in the same box).")
 
             common_args = ((morton_bin_counts, morton_nrs,
                     box_start_flags,
-- 
GitLab


From 81d56c9a342983c57c6ab93644fa7d347c56680c Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Thu, 22 Feb 2018 15:14:34 -0600
Subject: [PATCH 2/3] Fix max-levels error, add test

---
 boxtree/tree_build.py |  8 ++++++--
 test/test_tree.py     | 19 +++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/boxtree/tree_build.py b/boxtree/tree_build.py
index 42bc3bd..3fec8dc 100644
--- a/boxtree/tree_build.py
+++ b/boxtree/tree_build.py
@@ -36,6 +36,10 @@ import logging
 logger = logging.getLogger(__name__)
 
 
+class MaxLevelsExceeded(RuntimeError):
+    pass
+
+
 class TreeBuilder(object):
     def __init__(self, context):
         """
@@ -540,9 +544,9 @@ class TreeBuilder(object):
                 assert level == len(level_used_box_counts)
                 assert level == len(level_leaf_counts)
 
-            assert np.iinfo(self.box_level_dtype).max >= np.finfo(coord_dtype).mnant
+            assert np.iinfo(self.box_level_dtype).max >= np.finfo(coord_dtype).nmant
             if level > np.finfo(coord_dtype).nmant:
-                raise RuntimeError("Level count exceeded number of significant "
+                raise MaxLevelsExceeded("Level count exceeded number of significant "
                         "bits in coordinate dtype. That means that a large number "
                         "of particles was indistinguishable up to floating point "
                         "precision (because they ended up in the same box).")
diff --git a/test/test_tree.py b/test/test_tree.py
index f68a885..cf5e110 100644
--- a/test/test_tree.py
+++ b/test/test_tree.py
@@ -1122,6 +1122,25 @@ def test_same_tree_with_zero_weight_particles(ctx_factory, dims):
 # }}}
 
 
+# {{{ test_max_levels_error
+
+def test_max_levels_error(ctx_factory):
+    ctx = ctx_factory()
+    queue = cl.CommandQueue(ctx)
+
+    from boxtree import TreeBuilder
+    tb = TreeBuilder(ctx)
+
+    logging.basicConfig(level=logging.INFO)
+
+    sources = [cl.array.zeros(queue, 11, float) for i in range(2)]
+    from boxtree.tree_build import MaxLevelsExceeded
+    with pytest.raises(MaxLevelsExceeded):
+        tree, _ = tb(queue, sources, max_particles_in_box=10, debug=True)
+
+# }}}
+
+
 # You can test individual routines by typing
 # $ python test_tree.py 'test_routine(cl.create_some_context)'
 
-- 
GitLab


From 667cf7e63de6be8a433ead447178b397d718752e Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Thu, 22 Feb 2018 15:22:15 -0600
Subject: [PATCH 3/3] Improve nmax_levels logic

---
 boxtree/tree_build.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/boxtree/tree_build.py b/boxtree/tree_build.py
index 3fec8dc..b03c336 100644
--- a/boxtree/tree_build.py
+++ b/boxtree/tree_build.py
@@ -458,7 +458,8 @@ class TreeBuilder(object):
                 queue, box_parent_ids.data, np.zeros((), dtype=box_parent_ids.dtype))
         prep_events.append(evt)
 
-        nlevels_max = np.iinfo(self.box_level_dtype).max
+        nlevels_max = np.finfo(coord_dtype).nmant + 1  # num bits in the significand
+        assert nlevels_max <= np.iinfo(self.box_level_dtype).max
 
         # level -> starting box on level
         level_start_box_nrs_dev, evt = zeros(nlevels_max, dtype=box_id_dtype)
@@ -544,8 +545,7 @@ class TreeBuilder(object):
                 assert level == len(level_used_box_counts)
                 assert level == len(level_leaf_counts)
 
-            assert np.iinfo(self.box_level_dtype).max >= np.finfo(coord_dtype).nmant
-            if level > np.finfo(coord_dtype).nmant:
+            if level + 1 >= nlevels_max:  # level is zero-based
                 raise MaxLevelsExceeded("Level count exceeded number of significant "
                         "bits in coordinate dtype. That means that a large number "
                         "of particles was indistinguishable up to floating point "
-- 
GitLab