Deprecate proj3d.mod.

anntzer · anntzer · commit c5a64d277e44 · 2018-12-19T11:17:29.000+01:00
Having a function named mod that doesn't do % but computes the norm of a
vector is just a good way to trip the reader (yes, I know about the term
"modulus of a vector", but still).

Also vectorize a normals calculation.

Also we can use % instead of np.mod elsewhere.
diff --git a/doc/api/next_api_changes/2018-12-19-AL-deprecations.rst b/doc/api/next_api_changes/2018-12-19-AL-deprecations.rst
@@ -0,0 +1,5 @@
+Deprecations
+````````````
+
+``mpl_toolkits.mplot3d.proj3d.mod`` is deprecated; use `numpy.linalg.norm`
+instead.
diff --git a/lib/matplotlib/quiver.py b/lib/matplotlib/quiver.py
@@ -985,10 +985,10 @@ def _find_tails(self, mag, rounding=True, half=5, full=10, flag=50):
             mag = half * (mag / half + 0.5).astype(int)
 
         num_flags = np.floor(mag / flag).astype(int)
-        mag = np.mod(mag, flag)
+        mag = mag % flag
 
         num_barb = np.floor(mag / full).astype(int)
-        mag = np.mod(mag, full)
+        mag = mag % full
 
         half_flag = mag >= half
         empty_flag = ~(half_flag | (num_flags > 0) | (num_barb > 0))
diff --git a/lib/matplotlib/tri/triinterpolate.py b/lib/matplotlib/tri/triinterpolate.py
@@ -1135,7 +1135,7 @@ def compute_geom_weights(self):
             alpha2 = np.arctan2(p2[:, 1]-p0[:, 1], p2[:, 0]-p0[:, 0])
             # In the below formula we could take modulo 2. but
             # modulo 1. is safer regarding round-off errors (flat triangles).
-            angle = np.abs(np.mod((alpha2-alpha1) / np.pi, 1.))
+            angle = np.abs(((alpha2-alpha1) / np.pi) % 1)
             # Weight proportional to angle up np.pi/2; null weight for
             # degenerated cases 0 and np.pi (note that `angle` is normalized
             # by np.pi).
diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -1030,7 +1030,7 @@ def get_proj(self):
 
         self.eye = E
         self.vvec = R - E
-        self.vvec = self.vvec / proj3d.mod(self.vvec)
+        self.vvec = self.vvec / np.linalg.norm(self.vvec)
 
         if abs(relev) > np.pi/2:
             # upside down
@@ -1768,9 +1768,9 @@ def _shade_colors(self, color, normals, lightsource=None):
             # chosen for backwards-compatibility
             lightsource = LightSource(azdeg=225, altdeg=19.4712)
 
-        shade = np.array([np.dot(n / proj3d.mod(n), lightsource.direction)
-                          if proj3d.mod(n) else np.nan
-                          for n in normals])
+        with np.errstate(invalid="ignore"):
+            shade = ((normals / np.linalg.norm(normals, axis=1, keepdims=True))
+                     @ lightsource.direction)
         mask = ~np.isnan(shade)
 
         if mask.any():
diff --git a/lib/mpl_toolkits/mplot3d/proj3d.py b/lib/mpl_toolkits/mplot3d/proj3d.py
@@ -1,11 +1,12 @@
-# 3dproj.py
-#
 """
 Various transforms used for by the 3D code
 """
+
 import numpy as np
 import numpy.linalg as linalg
 
+from matplotlib import cbook
+
 
 def line2d(p0, p1):
     """
@@ -62,6 +63,7 @@ def line2d_seg_dist(p1, p2, p0):
     return d
 
 
+@cbook.deprecated("3.1", alternative="np.linalg.norm")
 def mod(v):
     """3d vector length"""
     return np.sqrt(v[0]**2+v[1]**2+v[2]**2)
@@ -80,9 +82,9 @@ def world_transformation(xmin, xmax,
 def view_transformation(E, R, V):
     n = (E - R)
     ## new
-#    n /= mod(n)
+#    n /= np.linalg.norm(n)
 #    u = np.cross(V,n)
-#    u /= mod(u)
+#    u /= np.linalg.norm(u)
 #    v = np.cross(n,u)
 #    Mr = np.diag([1.]*4)
 #    Mt = np.diag([1.]*4)
@@ -91,9 +93,9 @@ def view_transformation(E, R, V):
     ## end new
 
     ## old
-    n = n / mod(n)
+    n = n / np.linalg.norm(n)
     u = np.cross(V, n)
-    u = u / mod(u)
+    u = u / np.linalg.norm(u)
     v = np.cross(n, u)
     Mr = [[u[0], u[1], u[2], 0],
           [v[0], v[1], v[2], 0],
