DOC: fix inaccuracy in colormap tutorial

jklymak · jklymak · commit 5696953202a7 · 2021-11-23T13:35:56.000+01:00
diff --git a/tutorials/colors/colormap-manipulation.py b/tutorials/colors/colormap-manipulation.py
@@ -132,12 +132,13 @@ def plot_examples(colormaps):
 plot_examples([viridis, newcmp])
 
 ##############################################################################
-# We can easily reduce the dynamic range of a colormap; here we choose the
-# middle 0.5 of the colormap.  However, we need to interpolate from a larger
-# colormap, otherwise the new colormap will have repeated values.
+# We can reduce the dynamic range of a colormap; here we choose the
+# middle 0.5 of the colormap.  Note, however, that because viridis is a
+# listed colormap, some colors will be repeated when doing the nearest-neighbour
+# interpolation
 
-viridis_big = cm.get_cmap('viridis', 512)
-newcmp = ListedColormap(viridis_big(np.linspace(0.25, 0.75, 256)))
+viridis_big = cm.get_cmap('viridis', 256)
+newcmp = ListedColormap(viridis_big(np.linspace(0.25, 0.75, 128)))
 plot_examples([viridis, newcmp])
 
 ##############################################################################
