feat: add axis swap — left-right goes on horizontal axis when detected

explorer.py

@@ -170,6 +170,46 @@ def get_uniform_dim_windows(db_path: str) -> List[str]:
         con.close()
 
 
+def _should_swap_axes(axis_def: dict) -> bool:
+    """Return True if the Y axis is 'Links–Rechts' and the X axis is not.
+
+    When true, caller should swap x/y positions and metadata so left-right
+    is conventionally on the horizontal axis.
+    """
+    lr = "Links\u2013Rechts"
+    return axis_def.get("y_label") == lr and axis_def.get("x_label") != lr
+
+
+def _swap_axes(
+    positions_by_window: dict,
+    axis_def: dict,
+) -> tuple:
+    """Swap x and y in all positions and axis metadata.
+
+    Pure function — returns (new_positions_by_window, new_axis_def).
+    """
+    new_positions: dict = {}
+    for wid, pos_dict in positions_by_window.items():
+        new_positions[wid] = {ent: (y, x) for ent, (x, y) in pos_dict.items()}
+
+    new_ax = dict(axis_def)
+    # Swap paired scalar keys
+    new_ax["x_label"] = axis_def.get("y_label")
+    new_ax["y_label"] = axis_def.get("x_label")
+
+    # Swap paired dict keys
+    for x_key, y_key in [
+        ("x_quality", "y_quality"),
+        ("x_interpretation", "y_interpretation"),
+        ("x_top_motions", "y_top_motions"),
+        ("x_label_confidence", "y_label_confidence"),
+    ]:
+        new_ax[x_key] = axis_def.get(y_key)
+        new_ax[y_key] = axis_def.get(x_key)
+
+    return new_positions, new_ax
+
+
 @st.cache_data(show_spinner="2D posities berekenen (kan even duren)…")
 def load_positions(
     db_path: str, window_size: str = "quarterly"
@@ -210,6 +250,9 @@ def load_positions(
             "classify_axes failed; using generic axis labels"
         )
 
+    if _should_swap_axes(axis_def):
+        positions_by_window, axis_def = _swap_axes(positions_by_window, axis_def)
+
     # Filter displayed windows by window_size AFTER PCA computation.
     if window_size == "annual":
         annual_keys = set(w for w in all_available if "-Q" not in w)

tests/test_political_compass.py

@@ -111,6 +111,21 @@ except Exception:
     _go.Figure = lambda *a, **kw: None
     sys.modules["plotly.graph_objects"] = _go
 
+# Provide a minimal streamlit stub so explorer imports succeed in the test env
+try:
+    import streamlit as _st  # noqa: F401
+except Exception:
+    _st_stub = types.ModuleType("streamlit")
+    _st_stub.cache_data = lambda **kw: lambda f: f
+    _st_stub.plotly_chart = lambda *a, **kw: None
+    _st_stub.markdown = lambda *a, **kw: None
+    _st_stub.caption = lambda *a, **kw: None
+    _st_stub.error = lambda *a, **kw: None
+    _st_stub.warning = lambda *a, **kw: None
+    _st_stub.info = lambda *a, **kw: None
+    _st_stub.write = lambda *a, **kw: None
+    sys.modules["streamlit"] = _st_stub
+
 import pytest
 
 
@@ -654,3 +669,58 @@ def test_classify_from_titles_low_confidence():
     label, confidence = _classify_from_titles(titles)
     assert label is None
     assert confidence < 0.4
+
+
+def test_axis_swap_when_y_is_left_right():
+    """When y_label is 'Links–Rechts' and x_label is not, positions must be swapped."""
+    from explorer import _swap_axes
+
+    positions_by_window = {
+        "2023": {
+            "VVD": (0.5, 0.8),
+            "PvdA": (-0.3, -0.6),
+        }
+    }
+    axis_def = {
+        "x_label": "Progressief\u2013Conservatief",
+        "y_label": "Links\u2013Rechts",
+        "x_quality": {"2023": 0.7},
+        "y_quality": {"2023": 0.8},
+        "x_interpretation": {"2023": "prog interpretation"},
+        "y_interpretation": {"2023": "lr interpretation"},
+        "x_top_motions": {"2023": {"+": [], "-": []}},
+        "y_top_motions": {"2023": {"+": [], "-": []}},
+        "x_label_confidence": {"2023": 0.5},
+        "y_label_confidence": {"2023": 0.7},
+    }
+
+    new_pos, new_ax = _swap_axes(positions_by_window, axis_def)
+
+    # Positions swapped: (x, y) → (y, x)
+    assert new_pos["2023"]["VVD"] == (0.8, 0.5)
+    assert new_pos["2023"]["PvdA"] == (-0.6, -0.3)
+
+    # Labels swapped
+    assert new_ax["x_label"] == "Links\u2013Rechts"
+    assert new_ax["y_label"] == "Progressief\u2013Conservatief"
+
+    # Quality swapped
+    assert new_ax["x_quality"] == {"2023": 0.8}
+    assert new_ax["y_quality"] == {"2023": 0.7}
+
+
+def test_axis_swap_not_applied_when_x_is_left_right():
+    """When x_label is already 'Links–Rechts', no swap should occur."""
+    from explorer import _should_swap_axes
+
+    axis_def = {
+        "x_label": "Links\u2013Rechts",
+        "y_label": "Progressief\u2013Conservatief",
+    }
+    assert _should_swap_axes(axis_def) is False
+
+    axis_def2 = {
+        "x_label": "Links\u2013Rechts",
+        "y_label": "Links\u2013Rechts",  # both LR — no swap
+    }
+    assert _should_swap_axes(axis_def2) is False