Changeset 21c133 in git

Timestamp:

Jun 28, 2020, 10:26:42 AM (3 years ago)

Author:

Gergo Borus <gergo@…>

Branches:

(u'spielwiese', '828514cf6e480e4bafc26df99217bf2a1ed1ef45')

Children:

dc69b80290980f6110fcb3b9978c07da5f87863d

Parents:

a7235589fb2e045397d9d6de8846aeccb51f4074

git-author:

Gergo Borus <gergo@borus.hu>2020-06-28 10:26:42+02:00

git-committer:

Gergo Borus <gergo@borus.hu>2020-06-28 11:29:45+02:00

Message:

fix: tr. #638 (weighted degrees in ffsolve)

First example:
-y^2 + x^3 + x has indeed only 4 points, the actual Hermitian
curve -y^3  + x^2 + x has 8 and all of them are returned.

Second example:
simplesolver had an assumption about deg which did not hold for
weighted degrees.
The used method for extending the ring could not handle weighted
degrees.

Third example:
Limitation stemming from factorize.

File:

• Singular/LIB/ffsolve.lib (modified) (4 diffs)

Singular/LIB/ffsolve.lib

@@ -314 +314 @@
   ideal partial_system, curr_sol, curr_sys, factors;
   poly univar_poly;
+  intvec ones = 1:nvars(basering);
   E = E+defaultIdeal();
   // check assumptions
@@ -345 +346 @@
       for(j=1; j<=ncols(factors); j++)
       {
-        if(deg(factors[j])==1)
+        if(deg(factors[j], ones)==1)
         {
           curr_sol = std(solutions[i]+ideal(factors[j]));
@@ -851 +852 @@
     +get_minpoly_str(size(original_ring),parstr(original_ring,1))+";" ;
   }
-  string old_vars = varstr(original_ring);
-  string new_vars = "@y(1.."+string( number_of_monomials )+")";
-
-  def ring_for_var_change = changevar( old_vars+","+new_vars, original_ring);
+
+  def ring_for_var_change = addNvarsTo(original_ring, number_of_monomials, "@y", 2);
+ 
   setring ring_for_var_change;
   if( prime_field == 0)
@@ -877 +877 @@
   }
 
+  string new_vars = "@y(1.."+string( number_of_monomials )+")";
   def ring_for_elimination = changevar( new_vars, ring_for_var_change);
   setring ring_for_elimination;