Merge pull request malariagen#769 from malariagen/GH768-Null-se-can-raise-error

Handle ZeroDivisionError in plot_pairwise_average_fst

Author: leehart

malariagen_data/anoph/fst.py

@@ -539,8 +539,11 @@ def plot_pairwise_average_fst(
             if annotation == "standard error":
                 fig_df.loc[cohort1, cohort2] = se
             elif annotation == "Z score":
-                zs = fst / se
-                fig_df.loc[cohort1, cohort2] = zs
+                try:
+                    zs = fst / se
+                    fig_df.loc[cohort1, cohort2] = zs
+                except ZeroDivisionError:
+                    fig_df.loc[cohort1, cohort2] = np.nan
             else:
                 fig_df.loc[cohort1, cohort2] = fst