Added presentation in chow_ring.py

sagemath · Jan 21, 2025 · 1aabf83 · 1aabf83
1 parent 5c4c89d
commit 1aabf83
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Showing 2 changed files with 13 additions and 8 deletions.
diff --git a/src/sage/matroids/chow_ring.py b/src/sage/matroids/chow_ring.py
@@ -15,7 +15,7 @@
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from sage.matroids.chow_ring_ideal import ChowRingIdeal_nonaug, AugmentedChowRingIdeal_fy, AugmentedChowRingIdeal_atom_free
+from sage.matroids.chow_ring_ideal import ChowRingIdeal_nonaug_fy, ChowRingIdeal_nonaug_af, ChowRingIdeal_nonaug_sp, AugmentedChowRingIdeal_fy, AugmentedChowRingIdeal_atom_free
 from sage.rings.quotient_ring import QuotientRing_generic
 from sage.categories.kahler_algebras import KahlerAlgebras
 from sage.categories.commutative_rings import CommutativeRings
@@ -110,7 +110,12 @@ def __init__(self, R, M, augmented, presentation=None):
             elif presentation == 'atom-free':
                 self._ideal = AugmentedChowRingIdeal_atom_free(M, R)
         else:
-            self._ideal = ChowRingIdeal_nonaug(M, R)
+            if presentation == 'fy':
+                self._ideal = ChowRingIdeal_nonaug_fy(M, R)
+            if presentation == 'atom-free':
+                self._ideal = ChowRingIdeal_nonaug_af(M, R)
+            if presentation == 'simplicial':
+                self._ideal = ChowRingIdeal_nonaug_sp(M, R)
         C = CommutativeRings().Quotients() & KahlerAlgebras(R)
         QuotientRing_generic.__init__(self, R=self._ideal.ring(),
                                       I=self._ideal,

diff --git a/src/sage/matroids/chow_ring_ideal.py b/src/sage/matroids/chow_ring_ideal.py
@@ -99,12 +99,12 @@ def flats_to_generator_dict(self):
         return dict(self._flats_generator)
 
 
-class ChowRingIdeal_nonaug(ChowRingIdeal):
+class ChowRingIdeal_nonaug_fy(ChowRingIdeal):
     r"""
-    The Chow ring ideal of a matroid `M`.
+    The Chow ring ideal of a matroid `M` in Feitchner-Yuzvinsky presentation.
 
-    The *Chow ring ideal* for a matroid `M` is defined as the ideal
-    `(I_M + J_M)` of the polynomial ring
+    The *Chow ring ideal* for a matroid `M` in Feitchner-Yuzvinsky presentation
+    is defined as the ideal `(I_M + J_M)` of the polynomial ring
 
     .. MATH::
 
@@ -224,9 +224,9 @@ def _repr_(self):
             sage: ch = matroids.catalog.Fano().chow_ring(QQ, False)
             sage: ch.defining_ideal()
             Chow ring ideal of Fano: Binary matroid of rank 3 on 7 elements,
-            type (3, 0) - non augmented
+            type (3, 0) - non augmented in Feitchner-Yuzvinsky presentation
         """
-        return "Chow ring ideal of {} - non augmented".format(self._matroid)
+        return "Chow ring ideal of {} - non augmented in Feitchner-Yuzvinksy presentation".format(self._matroid)
 
     def _latex_(self):
         r"""