Changeset b24fe3 in git

Timestamp:

Nov 28, 2014, 11:49:45 AM (9 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'spielwiese', 'd1b01e9d51ade4b46b745d3bada5c5f3696be3a8')

Children:

ba19a8a94da4931a7c4fb8ea6bc91256251c15ec

Parents:

25e8609473c8b0c0bf29a493b620176e064e7790

Message:

chg: hasGFCoefficient

Location:

Singular/LIB

Files:

• hnoether.lib (modified) (3 diffs)
• ring.lib (modified) (2 diffs)

Singular/LIB/hnoether.lib

@@ -279 +279 @@
   if (size(parstr(altring))==1) { mipl=string(minpoly); }
  //---- test: char = (p^k,a) (-> gcd not implemented) or (p,a) (gcd works) ----
-  if ((char(basering)!=0) and (charstr(basering)!=string(char(basering)))) {
-    string tststr=charstr(basering);
-    tststr=tststr[1..find(tststr,",")-1];           //-> "p^k" bzw. "p"
-    gcd_ok=(tststr==string(char(basering)));
-  }
+  //if ((char(basering)!=0) and (charstr(basering)!=string(char(basering))))
+  gcd_ok= ! hasGFCoefficient(basering);
   execute("ring rsqrf = ("+charstr(altring)+"),(x,y),dp;");
   if ((gcd_ok!=0) && (mipl!="0")) { execute("minpoly="+mipl+";"); }
@@ -2740 +2737 @@
 
  //--------- Falls Ring (p^k,a),...: Wechsel in (p,a),... + minpoly -----------
- if ( (find(charstr(basering),string(char(basering)))!=1) &&
-      (charstr(basering)<>"real")&&
-      (charstr(basering)<>"complex") ) {
+ if ( hasGFCoefficient(basering) )
+ {
    string strmip=string(minpoly);
    string strf=string(f);
@@ -2907 +2903 @@
    " Warning: all variables except the first two will be ignored!");
  }
- if (find(charstr(basering),string(char(basering)))!=1) {
-   " ring of type (p^k,a) not implemented";
+ if (hasGFCoefficient(basering))
+ {
+   ERROR(" ring of type (p^k,a) not implemented");
  //----------------------------------------------------------------------------
  // weder primitives Element noch factorize noch map "char p^k" -> "char -p"
  // [(p^k,a)->(p,a) ground field] noch fetch
  //----------------------------------------------------------------------------
-   return(list());
  }
  //----------------- Definition eines neuen Ringes: HNEring -------------------
  string namex=varstr(1); string namey=varstr(2);
- if (string(char(altring))==charstr(altring)) { // kein Parameter, nicht 'real'
+ if ((npars(altring)==0)&&(find(charstr(altring),"real")==0)) { // kein Parameter, nicht 'real'
    ring HNEring = char(altring),(x,y),ls;
    map m=altring,x,y;

Singular/LIB/ring.lib

@@ -25 +25 @@
  optionIsSet(opt)         check if as a string given option is set or not.
  hasFieldCoefficient      check if the coefficient ring is considered a field
+ hasGFCoefficient         check if the coefficient ring is GF(p,k)
  hasNumericCoeffs(rng)    check for use of floating point numbers
  hasCommutativeVars(rng)  non-commutive or commnuative polynomial ring
@@ -996 +997 @@
 }
 
+proc hasGFCoefficient(def rng )
+"USAGE: hasGFCoefficient ( rng );
+RETURN:  1 if the coeffcients form GF(p,k), 0 otherwise.
+KEYWORDS: ring coefficients
+EXAMPLE: example hasGFCoefficient; shows an example
+"
+{
+  return((charstr(rng)!=string(char(rng))) &&
+  (npars(rng)==1) &&
+  (find(charstr(rng),string(char(rng)))!=1) &&
+  (charstr(basering)<>"real")&&
+  (charstr(basering)<>"complex") );
+}
+example
+{
+  ring r1 = integer,x,dp;
+  hasGF(r1);
+  ring r2 = (4,a),x,dp;
+  hasGF(r2);
+}
+
 proc hasGlobalOrdering (def rng)
 "USAGE: hasGlobalOrdering ( rng );