fix: fixed violin when data is all nan (#25)

Author: jlerat

hydrodiy/plot/tests/test_hyplot_violinplot.py

@@ -115,6 +115,17 @@ def test_violin_missing():
     fig.savefig(fp)
 
 
+def test_violin_allnan():
+    plt.close("all")
+    df = DATA1.copy()
+    df.iloc[:, 0] = np.nan
+    vl = Violin(data=df)
+    fig, ax = plt.subplots()
+    vl.draw(ax=ax)
+    fp = FIMG / "violin_allnan.png"
+    fig.savefig(fp)
+
+
 def test_violin_log():
     plt.close("all")
     vl = Violin(data=DATA2)

hydrodiy/plot/violinplot.py

@@ -210,9 +210,10 @@ def _compute(self):
         # Compute kde
         for cn, se in data.items():
             notnull = se.notnull()
-            if notnull.sum() <= 2:
-                errmess = f"Less than 2 valid data in {cn}."
-                raise ValueError(errmess)
+            if notnull.sum()<=2:
+                kde_x.loc[:, cn] = np.nan
+                kde_y.loc[:, cn] = np.nan
+                continue
 
             sen = se[notnull]
             kernel = gaussian_kde(sen.values)
@@ -253,6 +254,8 @@ def draw(self, ax=None):
         for i, colname in enumerate(kde_x.columns):
             # Get kde data
             x = kde_x.loc[:, colname]
+            if x.isnull().all():
+                continue
             y = kde_y.loc[:, colname]
 
             # initialise boxplot elements
@@ -344,3 +347,8 @@ def draw(self, ax=None):
         xt = np.arange(ncols)
         ax.set_xticks(xt)
         ax.set_xticklabels(kde_x.columns)
+
+        ncols = kde_x.shape[1]
+        xlim = (-vw, ncols-1+vw)
+        ax.set_xlim(xlim)
+