bug: fix padic regulator computation (#1360)

thofma · Jan 21, 2024 · 0526c55 · 0526c55 · thofma · Jan 21, 2024
1 parent 63f0f7a
commit 0526c55
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Showing 2 changed files with 33 additions and 7 deletions.
diff --git a/Project.toml b/Project.toml
@@ -1,6 +1,6 @@
 name = "Hecke"
 uuid = "3e1990a7-5d81-5526-99ce-9ba3ff248f21"
-version = "0.24.2"
+version = "0.24.3"
 
 [deps]
 AbstractAlgebra = "c3fe647b-3220-5bb0-a1ea-a7954cac585d"

diff --git a/examples/NFDB.jl b/examples/NFDB.jl
@@ -1177,32 +1177,51 @@ function _p_adic_regulator(K, p, fast::Bool = false)
     if fast
       try
         C, mC = completion_easy(K, P, prec)
-      catch
+      catch e
+        if !(e isa ErrorException && e.msg == "cannot deal with difficult primes yet")
+          rethrow()
+        end
         C, mC = completion(K, P, prec)
       end
     else
       C, mC = completion(K, P, prec)
     end
     Rmat = zero_matrix(C, r, r)
     D = Dict{nf_elem, elem_type(C)}()
+    good = true
     for i in 1:r
       for j in 1:r
-        Rmat[i, j] = _evaluate_log_of_fac_elem(mC, P, mA(A[i])(mU(U[j + 1])), D) # j + 1, because the fundamental units correspond to U[2],..,U[r + 1]
+        try
+          Rmat[i, j] = _evaluate_log_of_fac_elem(mC, P, mA(A[i])(mU(U[j + 1])), D) # j + 1, because the fundamental units correspond to U[2],..,U[r + 1]
+        catch e
+          if !(e isa ErrorException && e.msg == "precision too low")
+            rethrow()
+          end
+          good = false
+          break
+        end
       end
+      if !good
+        break
+      end
+    end
+    if !good
+      prec = 2*prec
+      continue
     end
     z = _det(Rmat)
     if !is_zero(z)
       return valuation(z)
     else
       prec = 2*prec
     end
-    if prec > 4048
+    if prec > 2^15
       error("Something wrong")
     end
   end
 end
 
-function _evaluate_log_of_fac_elem(mC, P, e::FacElem{nf_elem, AnticNumberField}, D = Dict{nf_elem, LocalFieldElem{qadic, EisensteinLocalField}}())
+function _evaluate_log_of_fac_elem(mC, P, e::FacElem{nf_elem, AnticNumberField}, D = Dict{nf_elem, elem_type(codomain(mC))}())
   C = codomain(mC)
   K = base_ring(e)
   pi = K(uniformizer(P))
@@ -1217,7 +1236,14 @@ function _evaluate_log_of_fac_elem(mC, P, e::FacElem{nf_elem, AnticNumberField},
   for (b, n) in e
     l = get!(D, b) do
       bb = mC(pi^(-valuation(b, P)) * b)
-      return log(bb)
+      if is_zero(bb)
+        error("precision too low")
+      end
+      if bb isa qadic
+        return _log(bb)
+      else
+        return log(bb)
+      end
     end
     res = res + n * l
   end
@@ -1233,7 +1259,7 @@ function _padic_regulator_non_normal(K, p)
   # first identify the distinct p-adic completions of K
   A, mA = automorphism_group(N)
   d = degree(N)
-  prec = 32 
+  prec = 32
   auts = Int[]
   while true
     empty!(auts)