From dd06bbec217a272c911a972d6830aa152917a226 Mon Sep 17 00:00:00 2001
From: Yu Cong <sxlxcsxlxc@gmail.com>
Date: Sun, 19 Oct 2025 23:48:01 +0800
Subject: [PATCH] fix bug

---
 projection.sage | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/projection.sage b/projection.sage
index 8f5ba2e..e6eb77e 100644
--- a/projection.sage
+++ b/projection.sage
@@ -30,13 +30,14 @@ def cogirthip(bases, integral=true):
 
 cnt=0   # actual number of instances tested
 f = lambda g: g.is_connected()
-for n in range(4,20):
-    for g in filter(f, graphs(n)):
+for N in range(8,20):
+    for g in filter(f, graphs(N)):
         A=g.incidence_matrix()
         n,m = A.dimensions()
         # enumerate all vectors in F_2^n with even number of 1s
-        V = VectorSpace(GF(2), n)
+        V = VectorSpace(GF(2), N)
         for v in filter(lambda v: v.hamming_weight() % 2 == 0 and v!=0, V):
+            cnt=cnt+1
             v_col=matrix(v).transpose()
             A_t=A.augment(v_col)
             # print(A_t)
@@ -46,9 +47,9 @@ for n in range(4,20):
             strength=cogirthip(bases,integral=false)
             cogirth =cogirthip(bases,integral=true)
             gap = cogirth/strength
-            if gap > 2.01:
+            if gap > 3.01:
                 print(f"bad example! gap={gap}")
-                with open("projection.out", "a") as f:
-                    f.write(str(gap)+"\n"+str(A_t)+"\n")
-            else:
-                print(f"n={n},m={m},gap={gap}")
\ No newline at end of file
+                with open("projection.out", "a") as file:
+                    file.write(str(gap)+"\n"+str(A_t)+"\n")
+            if cnt%100==0:
+                print(f"#{cnt},n={n},m={m}")
\ No newline at end of file