do not normalize binary arrays (issue765)

healpy · Jun 8, 2022 · 7b3a3c3 · 7b3a3c3
1 parent 0f46774
commit 7b3a3c3
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/healpy/projaxes.py b/healpy/projaxes.py
@@ -186,7 +186,12 @@ def projmap(
         if alpha is not None:
             alpha_img = self.proj.projmap(alpha, vec2pix_func, rot=rot, coord=coord)
             alpha_img[alpha_img == -np.inf] = 0
-            alpha = plt.Normalize()(alpha_img)
+            # If the alpha array is binary (e.g. 0's and some other value), do
+            # not normalize it
+            if np.unique(alpha_img).size <= 2:
+                alpha = alpha_img
+            else:
+                alpha = plt.Normalize()(alpha_img)
         try:
             if vmin is None:
                 vmin = img[w].min()