Merge branch 'pi-dev/csv-branch-info-in-header'

beta_spectrum/spectrum.py

@@ -1572,19 +1572,9 @@ class BetaSpectrumAnalyzer:
 
         if self._is_multi and self.spectrum.branches:
             # Multi-branch mode: total spectrum + per-branch spectra + components
-            for i, (branch, branch_spec) in enumerate(
-                zip(self.spectrum.branches, self.spectrum.branch_spectra)
-            ):
+            # (branch info — intensity, endpoint, transition — is in the header, not repeated columns)
+            for i, branch_spec in enumerate(self.spectrum.branch_spectra):
                 data[f"branch_{i+1}_spectrum"] = branch_spec(self.W)
-                data[f"branch_{i+1}_intensity"] = np.full_like(
-                    self.energies_MeV, branch.intensity
-                )
-                data[f"branch_{i+1}_endpoint"] = np.full_like(
-                    self.energies_MeV, branch.endpoint_MeV
-                )
-                data[f"branch_{i+1}_transition"] = np.full_like(
-                    self.energies_MeV, branch.transition_type, dtype=object
-                )
 
             # Per-branch components (PhaseSpace, Radiative, etc.)
             for i, branch_spec in enumerate(self.spectrum.branch_spectra):

tests/test_multi_branch.py

@@ -466,10 +466,18 @@ class TestMultiBranchCSVExport:
         # Should have total spectrum column
         assert "spectrum" in df.columns
 
-        # Should have per-branch columns
+        # Should have per-branch spectrum columns (intensity/endpoint/transition are in the header)
         assert "branch_1_spectrum" in df.columns
         assert "branch_2_spectrum" in df.columns
 
+        # Should NOT have repeated per-branch metadata columns
+        assert "branch_1_intensity" not in df.columns
+        assert "branch_1_endpoint" not in df.columns
+        assert "branch_1_transition" not in df.columns
+        assert "branch_2_intensity" not in df.columns
+        assert "branch_2_endpoint" not in df.columns
+        assert "branch_2_transition" not in df.columns
+
         # Should have universal columns
         assert "universal_Fermi" in df.columns