Rename 'Add' to 'sRGB_add'

trygvrad · trygvrad · commit b59850df968f · 2024-07-18T14:23:26.000+02:00
This renames the 'combination_mode' keywords from 'Add' and 'Sub' to  'sRGB_add' and 'sRGB_sub'. This change is intended to provide increased clarity if/when additional keywords are added.
diff --git a/lib/matplotlib/_cm_multivar.py b/lib/matplotlib/_cm_multivar.py
@@ -158,9 +158,9 @@
 
 cmap_families = {
     '2VarAddA': MultivarColormap('2VarAddA', [cmaps['2VarAddA' + str(i)] for
-                                              i in range(2)], 'Add'),
+                                              i in range(2)], 'sRGB_add'),
     '2VarSubA': MultivarColormap('2VarSubA', [cmaps['2VarSubA' + str(i)] for
-                                              i in range(2)], 'Sub'),
+                                              i in range(2)], 'sRGB_sub'),
     '3VarAddA': MultivarColormap('3VarAddA', [cmaps['3VarAddA' + str(i)] for
-                                              i in range(3)], 'Add'),
+                                              i in range(3)], 'sRGB_add'),
 }
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -1267,12 +1267,12 @@ def __init__(self, name, colormaps, combination_mode):
             The name of the colormap family.
         colormaps: list or tuple of `~matplotlib.colors.Colormap` objects
             The individual colormaps that are combined
-        combination_mode: str, 'Add' or 'Sub'
+        combination_mode: str, 'sRGB_add' or 'sRGB_sub'
             Describe how colormaps are combined in sRGB space
 
-            - If 'Add' -> Mixing produces brighter colors
+            - If 'sRGB_add' -> Mixing produces brighter colors
               `sRGB = cmap[0][X[0]] + cmap[1][x[1]] + ... + cmap[n-1][x[n-1]]`
-            - If 'Sub' -> Mixing produces darker colors
+            - If 'sRGB_sub' -> Mixing produces darker colors
               `sRGB = cmap[0][X[0]] + cmap[1][x[1]] + ... + cmap[n-1][x[n-1]] - n + 1`
         """
         self.name = name
@@ -1291,8 +1291,8 @@ def __init__(self, name, colormaps, combination_mode):
                                      " Colormap or valid strings.")
 
         self._colormaps = colormaps
-        if combination_mode not in ['Add', 'Sub']:
-            raise ValueError("Combination_mode must be 'Add' or 'Sub',"
+        if combination_mode not in ['sRGB_add', 'sRGB_sub']:
+            raise ValueError("Combination_mode must be 'sRGB_add' or 'sRGB_sub',"
                              f" {combination_mode!r} is not allowed.")
         self._combination_mode = combination_mode
         self.n_variates = len(colormaps)
@@ -1340,7 +1340,7 @@ def __call__(self, X, alpha=None, bytes=False, clip=True):
             rgba[..., 3] *= sub_rgba[..., 3]  # multiply alpha
             mask_bad |= sub_mask_bad
 
-        if self.combination_mode == 'Sub':
+        if self.combination_mode == 'sRGB_sub':
             rgba[..., :3] -= len(self) - 1
 
         rgba[mask_bad] = self.get_bad()
diff --git a/lib/matplotlib/tests/test_multivariate_colormaps.py b/lib/matplotlib/tests/test_multivariate_colormaps.py
@@ -41,7 +41,7 @@ def test_bivariate_cmap_shapes():
 def test_multivar_creation():
     # test creation of a custom multivariate colorbar
     blues = mpl.colormaps['Blues']
-    cmap = mpl.colors.MultivarColormap('custom', (blues, 'Oranges'), 'Sub')
+    cmap = mpl.colors.MultivarColormap('custom', (blues, 'Oranges'), 'sRGB_sub')
     y, x = np.mgrid[0:3, 0:3]/2
     im = cmap((y, x))
     res = np.array([[[0.96862745, 0.94509804, 0.92156863, 1],
@@ -56,11 +56,11 @@ def test_multivar_creation():
     assert_allclose(im,  res, atol=0.01)
 
     with pytest.raises(ValueError, match="colormaps must be a list of"):
-        cmap = mpl.colors.MultivarColormap('custom', (blues, [blues]), 'Sub')
+        cmap = mpl.colors.MultivarColormap('custom', (blues, [blues]), 'sRGB_sub')
     with pytest.raises(ValueError, match="A MultivarColormap must"):
-        cmap = mpl.colors.MultivarColormap('custom', 'blues', 'Sub')
+        cmap = mpl.colors.MultivarColormap('custom', 'blues', 'sRGB_sub')
     with pytest.raises(ValueError, match="A MultivarColormap must"):
-        cmap = mpl.colors.MultivarColormap('custom', (blues), 'Sub')
+        cmap = mpl.colors.MultivarColormap('custom', (blues), 'sRGB_sub')
 
 
 @image_comparison(["multivar_alpha_mixing.png"])
@@ -72,7 +72,7 @@ def test_multivar_alpha_mixing():
     alpha[:, 3] = np.linspace(1, 0, 256)
     alpha_cmap = mpl.colors.LinearSegmentedColormap.from_list('from_list', alpha)
 
-    cmap = mpl.colors.MultivarColormap('custom', (rainbow, alpha_cmap), 'Add')
+    cmap = mpl.colors.MultivarColormap('custom', (rainbow, alpha_cmap), 'sRGB_add')
     y, x = np.mgrid[0:10, 0:10]/9
     im = cmap((y, x))
 
@@ -185,7 +185,7 @@ def test_multivar_cmap_call():
 
 def test_multivar_bad_mode():
     cmap = mpl.multivar_colormaps['2VarSubA']
-    with pytest.raises(ValueError, match="Combination_mode must be 'Add' or 'Sub'"):
+    with pytest.raises(ValueError, match="Combination_mode must be 'sRGB_add' or"):
         cmap = mpl.colors.MultivarColormap('', cmap[:], 'bad')
 
 
@@ -508,7 +508,7 @@ def test_multivar_eq():
 
     cmap_1 = mpl.colors.MultivarColormap('2VarAddA',
                                          [cmap_0[0]]*2,
-                                         'Add')
+                                         'sRGB_add')
     assert (cmap_0 == cmap_1) is False
 
     cmap_1 = mpl.multivar_colormaps['3VarAddA']
@@ -519,5 +519,5 @@ def test_multivar_eq():
     assert (cmap_0 == cmap_1) is False
 
     cmap_1 = mpl.multivar_colormaps['2VarAddA']
-    cmap_1 = mpl.colors.MultivarColormap('', cmap_1[:], 'Sub')
+    cmap_1 = mpl.colors.MultivarColormap('', cmap_1[:], 'sRGB_sub')
     assert (cmap_0 == cmap_1) is False
