Fixes #124

docs/examples/advanced_examples/plot_4_misc_chain_visuals.py

@@ -112,3 +112,19 @@
 # It's beautiful. And it's hard to find a nice balance.
 c.set_override(ChainConfig(smooth=0, bins=100))
 fig = c.plotter.plot()
+
+
+# %%
+# Controlling the legend
+# ----------------------
+#
+# Sometimes we have a bunch of things we want to show, whether they are
+# chains, markers, truth values, or something else. By default, ChainConsumer
+# will try to show everything, but you specifically tell it to hide items on
+# the legend.
+
+
+c = ChainConsumer()
+c.add_chain(Chain(samples=df1, name="I'm in the legend!"))
+c.add_chain(Chain(samples=df2, name="I'm not!", show_label_in_legend=False))
+fig = c.plotter.plot()

src/chainconsumer/chain.py

@@ -137,6 +137,10 @@ class Chain(ChainConfig):
         default=1.0,
         description="Raise the posterior surface to this. Useful for inflating or deflating uncertainty for debugging.",
     )
+    show_label_in_legend: bool = Field(
+        default=True,
+        description="Whether to show the label in the legend",
+    )
 
     @property
     def data_columns(self) -> list[str]:
@@ -218,7 +222,7 @@ def _validate_color(cls, v: str | np.ndarray | list[float] | None) -> str | None
     def _copy_df(cls, v: pd.DataFrame) -> pd.DataFrame:
         return v.copy()
 
-    @model_validator(mode="after")
+    @model_validator(mode="after")  # type: ignore
     def _validate_model(self) -> Chain:
         assert not self.samples.empty, "Your chain is empty. This is not ideal."
 

src/chainconsumer/plotter.py

@@ -63,6 +63,8 @@ def get_size(
 def get_artists_from_chains(chains: list[Chain]) -> list[Artist]:
     artists: list[Artist] = []
     for chain in chains:
+        if not chain.show_label_in_legend:
+            continue
         if chain.plot_contour and not chain.plot_point:
             artists.append(
                 Line2D(
@@ -241,10 +243,11 @@ def plot(
             if "markerfirst" not in legend_kwargs:
                 legend_kwargs["markerfirst"] = legend_outside or not self.config.legend_artists
 
-            artists = get_artists_from_chains(base.chains)
+            chains_to_show_on_legend = [c for c in base.chains if c.show_label_in_legend]
+            artists = get_artists_from_chains(chains_to_show_on_legend)
             leg = ax.legend(handles=artists, **legend_kwargs)
             if self.config.legend_color_text:
-                for text, chain in zip(leg.get_texts(), base.chains):
+                for text, chain in zip(leg.get_texts(), chains_to_show_on_legend):
                     text.set_fontweight("medium")
                     text.set_color(colors.format(chain.color))
         fig.canvas.draw()