Avoid memory copies with np.full

rth · rth · commit 5a1e7b3b9964 · 2019-01-22T14:24:23.000+01:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -4000,7 +4000,7 @@ def dopatch(xs, ys, **kwargs):
             # maybe draw the fliers
             if showfliers:
                 # fliers coords
-                flier_x = np.ones(len(stats['fliers'])) * pos
+                flier_x = np.full(len(stats['fliers']), pos)
                 flier_y = stats['fliers']
 
                 fliers.extend(doplot(
diff --git a/lib/matplotlib/hatch.py b/lib/matplotlib/hatch.py
@@ -169,7 +169,7 @@ def __init__(self, hatch, density):
         self.num_rows = (hatch.count('*')) * density
         path = Path.unit_regular_star(5)
         self.shape_vertices = path.vertices
-        self.shape_codes = np.ones(len(self.shape_vertices)) * Path.LINETO
+        self.shape_codes = np.full(len(self.shape_vertices), Path.LINETO)
         self.shape_codes[0] = Path.MOVETO
         Shapes.__init__(self, hatch, density)
 
diff --git a/lib/matplotlib/legend_handler.py b/lib/matplotlib/legend_handler.py
@@ -231,7 +231,7 @@ def create_artists(self, legend, orig_handle,
         xdata, xdata_marker = self.get_xdata(legend, xdescent, ydescent,
                                              width, height, fontsize)
 
-        ydata = ((height - ydescent) / 2.) * np.ones(xdata.shape, float)
+        ydata = np.full(xdata.shape, ((height - ydescent) / 2.), float)
         legline = Line2D(xdata, ydata)
 
         self.update_prop(legline, orig_handle, legend)
diff --git a/lib/matplotlib/path.py b/lib/matplotlib/path.py
@@ -312,7 +312,7 @@ def make_compound_path_from_polys(cls, XY):
         stride = numsides + 1
         nverts = numpolys * stride
         verts = np.zeros((nverts, 2))
-        codes = np.ones(nverts, int) * cls.LINETO
+        codes = np.full(nverts, cls.LINETO, dtype=int)
         codes[0::stride] = cls.MOVETO
         codes[numsides::stride] = cls.CLOSEPOLY
         for i in range(numsides):
@@ -552,7 +552,7 @@ def interpolated(self, steps):
         vertices = simple_linear_interpolation(self.vertices, steps)
         codes = self.codes
         if codes is not None:
-            new_codes = Path.LINETO * np.ones(((len(codes) - 1) * steps + 1, ))
+            new_codes = np.full(((len(codes) - 1) * steps + 1, ), Path.LINETO)
             new_codes[0::steps] = codes
         else:
             new_codes = None
@@ -802,7 +802,7 @@ def unit_circle_righthalf(cls):
 
                 float)
 
-            codes = cls.CURVE4 * np.ones(14)
+            codes = np.full(14, cls.CURVE4)
             codes[0] = cls.MOVETO
             codes[-1] = cls.CLOSEPOLY
 
@@ -864,7 +864,7 @@ def arc(cls, theta1, theta2, n=None, is_wedge=False):
         if is_wedge:
             length = n * 3 + 4
             vertices = np.zeros((length, 2), float)
-            codes = cls.CURVE4 * np.ones((length, ), cls.code_type)
+            codes = np.full((length, ), cls.CURVE4, dtype=cls.code_type)
             vertices[1] = [xA[0], yA[0]]
             codes[0:2] = [cls.MOVETO, cls.LINETO]
             codes[-2:] = [cls.LINETO, cls.CLOSEPOLY]
@@ -873,7 +873,7 @@ def arc(cls, theta1, theta2, n=None, is_wedge=False):
         else:
             length = n * 3 + 1
             vertices = np.empty((length, 2), float)
-            codes = cls.CURVE4 * np.ones((length, ), cls.code_type)
+            codes = np.full((length, ), cls.CURVE4, dtype=cls.code_type)
             vertices[0] = [xA[0], yA[0]]
             codes[0] = cls.MOVETO
             vertex_offset = 1
diff --git a/lib/matplotlib/tri/triinterpolate.py b/lib/matplotlib/tri/triinterpolate.py
@@ -959,7 +959,7 @@ def get_Kff_and_Ff(self, J, ecc, triangles, Uc):
         """
         ntri = np.size(ecc, 0)
         vec_range = np.arange(ntri, dtype=np.int32)
-        c_indices = -np.ones(ntri, dtype=np.int32)  # for unused dofs, -1
+        c_indices = np.full(ntri, -1, dtype=np.int32)  # for unused dofs, -1
         f_dof = [1, 2, 4, 5, 7, 8]
         c_dof = [0, 3, 6]
 
diff --git a/lib/matplotlib/tri/trirefine.py b/lib/matplotlib/tri/trirefine.py
@@ -111,7 +111,7 @@ def refine_triangulation(self, return_tri_index=False, subdiv=3):
             # We have to initialize found_index with -1 because some nodes
             # may very well belong to no triangle at all, e.g., in case of
             # Delaunay Triangulation with DuplicatePointWarning.
-            found_index = - np.ones(refi_npts, dtype=np.int32)
+            found_index = np.full(refi_npts, -1, dtype=np.int32)
             tri_mask = self._triangulation.mask
             if tri_mask is None:
                 found_index[refi_triangles] = np.repeat(ancestors,
@@ -243,7 +243,7 @@ def _refine_triangulation_once(triangulation, ancestors=None):
                                          np.arange(ntri, dtype=np.int32)]))
         edge_apexes = np.ravel(np.vstack([np.zeros(ntri, dtype=np.int32),
                                           np.ones(ntri, dtype=np.int32),
-                                          np.ones(ntri, dtype=np.int32)*2]))
+                                          np.full(ntri, 2, dtype=np.int32)]))
         edge_neighbors = neighbors[edge_elems, edge_apexes]
         mask_masters = (edge_elems > edge_neighbors)
 
diff --git a/lib/matplotlib/tri/tritools.py b/lib/matplotlib/tri/tritools.py
@@ -292,7 +292,7 @@ def _total_to_compress_renum(mask, n=None):
         if n is None:
             n = np.size(mask)
         if mask is not None:
-            renum = -np.ones(n, dtype=np.int32)  # Default num is -1
+            renum = np.full(n, -1, dtype=np.int32)  # Default num is -1
             valid = np.arange(n, dtype=np.int32).compress(~mask, axis=0)
             renum[valid] = np.arange(np.size(valid, 0), dtype=np.int32)
             return renum
