fix nms-py

model/utils/nms/_nms_gpu_post_py.py

@@ -6,7 +6,8 @@ def _nms_gpu_post( mask,
                    threads_per_block,
                    col_blocks
                   ):
-
+    n_selection = 0
+    one_ull = np.array([1],dtype=np.uint64)
     selection = np.zeros((n_bbox,), dtype=np.int32)
     remv = np.zeros((col_blocks,), dtype=np.uint64)
 

model/utils/nms/non_maximum_suppression.py

@@ -5,6 +5,11 @@ import torch as t
 try:
     from ._nms_gpu_post import _nms_gpu_post
 except:
+    import warnings
+    warnings.warn('''
+    the python code for non_maximum_suppression is about 2x slow
+    It is strongly recommended to build cython code: 
+    `cd model/utils/nms/; python3 build.py build_ext --inplace''')
     from ._nms_gpu_post_py import _nms_gpu_post