fix(remap): in_place always making a copy (#52)

* fix(remap): in_place=True would always make a copy

* test: check if in_place actually changes underlying array

* docs: use more natural cython binding for remap, renumber for help

Author: william-silversmith

automated_test.py

@@ -213,6 +213,19 @@ def test_remap_broken():
   res = fastremap.remap(labels, {5:5}, preserve_missing_labels=True)
   assert np.all(res == labels)
 
+def test_remap_in_place_broken():
+  data = np.array([0])
+  result = fastremap.remap(data, {0: 1}, in_place=True)
+  assert result[0] == 1
+  assert data[0] == 1
+
+def test_renumber_in_place_broken():
+  data = np.array([5])
+  result, mapping = fastremap.renumber(data, in_place=True)
+  assert result[0] == 1
+  assert data[0] == 1
+  assert mapping == { 0: 0, 5: 1 }
+
 @pytest.mark.parametrize("dtype", DTYPES)
 @pytest.mark.parametrize("in_place", [ True, False ])
 def test_mask(dtype, in_place):

fastremap/fastremap.pyx

@@ -118,10 +118,9 @@ def indices(cnp.ndarray[NUMBER, cast=True, ndim=1] arr, NUMBER value):
 
   return np.asarray(all_indices, dtype=np.uint64)
 
+@cython.binding(True)
 def renumber(arr, start=1, preserve_zero=True, in_place=False):
   """
-  renumber(arr, start=1, preserve_zero=True, in_place=False)
-
   Given an array of integers, renumber all the unique values starting
   from 1. This can allow us to reduce the size of the data width required
   to represent it.
@@ -652,11 +651,9 @@ def _inverse_component_map(
 
   return remap
 
+@cython.binding(True)
 def remap(arr, table, preserve_missing_labels=False, in_place=False):
   """
-  remap(cnp.ndarray[COMPLEX_NUMBER] arr, dict table, 
-    preserve_missing_labels=False, in_place=False)
-
   Remap an input numpy array in-place according to the values in the given 
   dictionary "table".   
 
@@ -687,10 +684,12 @@ def remap(arr, table, preserve_missing_labels=False, in_place=False):
     arr = refit(arr, fit_value, increase_only=True)
 
   make_copy = (
-    (not in_place)
-    or (original_dtype == arr.dtype) # avoid two copies b/c copied in refit
-    or (not arr.flags.writeable)
-    or not (arr.flags.f_contiguous or arr.flags.c_contiguous)
+    (
+      (not in_place)
+      or (not arr.flags.writeable)
+      or not (arr.flags.f_contiguous or arr.flags.c_contiguous)
+    )
+    and (original_dtype == arr.dtype) # avoid two copies b/c copied in refit if dtype doesn't match
   )
 
   if make_copy: