refactor: use scatter plot format for SVD components 3-10

- Changed _render_party_axis_chart_1d from horizontal bar chart to scatter plot
- Same format as components 1-2: markers on horizontal line with axis arrows- Axis labels now show correct direction with arrows (← left | right →)
- Ensures consistent visualization across all SVD components

explorer.py

@@ -1357,7 +1357,10 @@ def _render_party_axis_chart_1d(
     comp_sel: int,
     theme: dict,
 ) -> None:
-    """Render a 1D horizontal bar chart of party positions on SVD component `comp_sel`.
+    """Render a 1D horizontal scatter of party positions on SVD component `comp_sel`.
+
+    Uses the same format as components 1-2: parties as markers on a horizontal line
+    with axis title showing poles with arrows.
 
     Args:
         party_coords: Dict mapping party name to tuple of scores (score_for_comp,)
@@ -1371,53 +1374,85 @@ def _render_party_axis_chart_1d(
         return
 
     # Extract scores and parties
-    parties = list(party_coords.keys())
-    scores = [coords[0] for coords in party_coords.values()]
+    parties = []
+    scores = []
+    colours = []
 
-    # Apply flip if needed
+    for party, coords in party_coords.items():
+        try:
+            score = float(coords[0])
+            parties.append(party)
+            scores.append(score)
+            colours.append(PARTY_COLOURS.get(party, "#9E9E9E"))
+        except Exception:
+            continue
+
+    if not scores:
+        st.caption("_Partijdata niet beschikbaar voor deze as._")
+        return
+
+    # Apply flip if needed (ensures right parties appear on right side)
     flip = theme.get("flip", False)
     if flip:
         scores = [-s for s in scores]
 
-    # Get party colors
-    party_colors = [PARTY_COLOURS.get(p, "#9E9E9E") for p in parties]
+    # Build hover text
+    hover = [f"{p}: {s:.3f}" for p, s in zip(parties, scores)]
 
-    # Sort by score for better visualization
-    sorted_indices = np.argsort(scores)
-    sorted_parties = [parties[i] for i in sorted_indices]
-    sorted_scores = [scores[i] for i in sorted_indices]
-    sorted_colors = [party_colors[i] for i in sorted_indices]
-
-    # Create horizontal bar chart
+    # Create figure with same format as components 1-2
     fig = go.Figure()
+    x_min, x_max = min(scores) * 1.15, max(scores) * 1.15
+    if x_min == x_max:
+        x_min, x_max = x_min - 1, x_max + 1
 
+    # Add horizontal axis line
     fig.add_trace(
-        go.Bar(
-            y=sorted_parties,
-            x=sorted_scores,
-            orientation="h",
-            marker_color=sorted_colors,
-            text=[f"{s:.2f}" for s in sorted_scores],
-            textposition="outside",
-        )
-    )
-
-    # Update layout
-    label = theme.get("label", f"As {comp_sel}")
-    positive_pole = theme.get("positive_pole", "Positief")
-    negative_pole = theme.get("negative_pole", "Negatief")
-
-    fig.update_layout(
-        title=f"Partijposities — {label}",
-        xaxis_title=f"{negative_pole} ← → {positive_pole}",
-        yaxis_title="",
-        height=max(400, len(parties) * 25),
-        margin=dict(l=150),
+        go.Scatter(
+            x=[x_min, x_max],
+            y=[0, 0],
+            mode="lines",
+            line={"color": "#cccccc", "width": 1},
+            hoverinfo="skip",
             showlegend=False,
         )
+    )
 
-    # Add vertical line at x=0
-    fig.add_vline(x=0, line_dash="dash", line_color="gray", opacity=0.5)
+    # Add party markers
+    fig.add_trace(
+        go.Scatter(
+            x=scores,
+            y=[0] * len(scores),
+            mode="markers+text",
+            text=parties,
+            textposition="top center",
+            marker={"size": 14, "color": colours},
+            hovertext=hover,
+            hoverinfo="text",
+            showlegend=False,
+        )
+    )
+
+    # Determine pole labels based on flip
+    pos_pole = theme.get("positive_pole", "")
+    neg_pole = theme.get("negative_pole", "")
+    left_label = pos_pole if flip else neg_pole
+    right_label = neg_pole if flip else pos_pole
+
+    # Update layout with same format as components 1-2
+    fig.update_layout(
+        height=160,
+        margin={"l": 10, "r": 10, "t": 10, "b": 30},
+        xaxis={
+            "title": f"← {left_label}  |  {right_label} →",
+            "showticklabels": False,
+            "showline": False,
+            "showgrid": False,
+            "zeroline": False,
+        },
+        yaxis={"visible": False, "range": [-1, 2]},
+        plot_bgcolor="rgba(0,0,0,0)",
+        paper_bgcolor="rgba(0,0,0,0)",
+    )
 
     st.plotly_chart(fig, use_container_width=True)
 

tests/test_explorer_chart.py

@@ -281,7 +281,7 @@ def test_partial_party_traces():
 
 
 def test_render_party_axis_chart_1d_renders():
-    """Test that _render_party_axis_chart_1d creates a figure with proper structure."""
+    """Test that _render_party_axis_chart_1d creates a scatter plot with markers (same format as components 1-2)."""
     from unittest.mock import MagicMock, patch
 
     from explorer import _render_party_axis_chart_1d
@@ -310,8 +310,12 @@ def test_render_party_axis_chart_1d_renders():
         # Get the figure passed to plotly_chart
         fig = mock_plotly_chart.call_args[0][0]
         assert fig is not None, "Figure should not be None"
-        # Check that figure has traces (the bar chart)
-        assert len(fig.data) > 0, "Figure should have traces"
+        # Check that figure has 2 traces (baseline line + markers)
+        assert len(fig.data) == 2, "Figure should have 2 traces (baseline + markers)"
+        # First trace is the baseline line
+        assert fig.data[0].mode == "lines", "First trace should be a line"
+        # Second trace is the marker scatter
+        assert "markers" in fig.data[1].mode, "Second trace should have markers"
 
 
 def test_render_party_axis_chart_1d_empty_coords():