changed RingElement / Number and Permanents::glynn

Macaulay2 · Aug 14, 2024 · 004fd42 · 004fd42
1 parent 80e30c8
commit 004fd42
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Showing 3 changed files with 16 additions and 3 deletions.
diff --git a/M2/Macaulay2/m2/enginering.m2 b/M2/Macaulay2/m2/enginering.m2
@@ -641,11 +641,13 @@ RingElement / RingElement := RingElement => (f,g) -> (
      f / g)
 frac0 = (f,g) -> f/g
 
+-- TODO: should these be more uniform? see 3e329d60815 and 13675361300
 Number / RingElement := frac0 @@ promoteleftexact
-RingElement / Number := (f,g) -> (1/g) * f
+RingElement / Number := (f, g) -> if f % g == 0 then f // g else (1/g) * f
 
+-- Note: % is not implemented for inexact fields
 InexactNumber / RingElement := frac0 @@ promoteleftinexact
-RingElement / InexactNumber := (f,g) -> (1/g) * f
+RingElement / InexactNumber := (f, g) -> (1/g) * f
 
 fraction(RingElement,RingElement) := (r,s) -> (
      R := ring r;

diff --git a/M2/Macaulay2/packages/Permanents.m2 b/M2/Macaulay2/packages/Permanents.m2
@@ -151,7 +151,7 @@ glynn Matrix := (M) -> (
 
       --need to divide in Glynn's formula
       --so can't be characteristic 2
-      perm=perm//2^(n-1);
+      perm = perm / 2^(n-1);
       perm
 )
 

diff --git a/M2/Macaulay2/tests/normal/reals.m2 b/M2/Macaulay2/tests/normal/reals.m2
@@ -13,3 +13,14 @@ scan({ZZ, QQ, RR, CC}, F -> (
 
 assert((pi*ii) // (3*ii) == 1)
 assert((pi*ii) %  (3*ii) + 3*ii == pi*ii)
+
+R = ZZ[x]
+f = (2*x+2)^3
+assert same {(x+1)^3, f // 8, f / 8}
+assert same {(x+1)*x, f // 16}
+assert(try f / 16 then false else true)
+
+R = QQ[x]
+f = (2*x+2)^3
+assert same {(x+1)^3,   f // 8,  f / 8}
+assert same {(x+1)^3/2, f // 16, f / 16}