Changeset 90d772 in git for Singular/LIB/general.lib

Timestamp:

May 2, 2005, 3:28:15 PM (18 years ago)

Author:

Hans Schönemann <hannes@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'a800fe4b3e9d37a38c5a10cc0ae9dfa0c15a4ee6')

Children:

c4e65ede88881de04fe2115143cd0fb9a0e67317

Parents:

17695492ed27b2e174eb4ae917d029b1027d83a9

Message:

*hannes: timeStd, time Factorize, factorH: standard.lib -> general.lib


git-svn-id: file:///usr/local/Singular/svn/trunk@7996 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• Singular/LIB/general.lib (modified) (3 diffs)

Singular/LIB/general.lib

@@ -3 +3 @@
 //eric, added absValue 11.04.2002
 ///////////////////////////////////////////////////////////////////////////////
-version="$Id: general.lib,v 1.44 2004-08-13 14:09:21 Singular Exp $";
+version="$Id: general.lib,v 1.45 2005-05-02 13:28:15 Singular Exp $";
 category="General purpose";
 info="
@@ -27 +27 @@
  which(command);        search for command and return absolute path, if found
  primecoeffs(J[,q]);    primefactors <= min(p,32003) of coeffs of J
- primefactors(n [,p]);  primefactors <= min(p,32003) of n
+ primefactors(n[,p]);  primefactors <= min(p,32003) of n
+ timeStd(i,d)           std(i) if the standard basis computation finished
+                        after d-1 seconds and i otherwhise
+ timeFactorize(p,d)     factorize(p) if the factorization finished after d-1
+                        seconds otherwhise f is considered to be irreducible
+ factorH(p)             changes variables to become the last variable the
+                        principal one in the multivariate factorization and
+                        factorizes then the polynomial
+
            (parameters in square brackets [] are optional)
 ";
@@ -1506 +1514 @@
 }
 ///////////////////////////////////////////////////////////////////////////////
+proc timeFactorize(poly i,list #)
+"USAGE:  timeFactorize(p,d)  poly p , integer d
+RETURN:  factorize(p) if the factorization finished after d-1 
+         seconds otherwhise f is considered to be irreducible
+EXAMPLE: example timeFactorize; shows an example
+"
+{
+  def P=basering;
+  if (size(#) > 0)
+  {
+    if (system("with", "MP"))
+    {
+      if ((typeof(#[1]) == "int")&&(#[1]))
+      {
+        int wait = #[1];
+        int j = 10;
+
+        string bs = nameof(basering);
+        link l_fork = "MPtcp:fork";
+        open(l_fork);
+        write(l_fork, quote(system("pid")));
+        int pid = read(l_fork);
+        write(l_fork, quote(timeFactorize(eval(i))));
+
+        // sleep in small intervalls for appr. one second
+        if (wait > 0)
+        {
+          while(j < 1000000)
+          {
+            if (status(l_fork, "read", "ready", j)) {break;}
+            j = j + j;
+          }
+        }
+
+        // sleep in intervalls of one second from now on
+        j = 1;
+        while (j < wait)
+        {
+          if (status(l_fork, "read", "ready", 1000000)) {break;}
+          j = j + 1;
+        }
+
+        if (status(l_fork, "read", "ready"))
+        {
+          def result = read(l_fork);
+          if (bs != nameof(basering))
+          {
+            def PP = basering;
+            setring P;
+            def result = imap(PP, result);
+            kill PP;
+          }
+          kill (l_fork);
+        }
+        else
+        {
+          list result;
+          intvec v=1,1;
+          result[1]=list(1,i);
+          result[2]=v;
+          j = system("sh", "kill " + string(pid));
+        }
+        return (result);
+      }
+    }
+  }
+  return(factorH(i));
+}
+example
+{ "EXAMPLE:"; echo = 2;
+   ring r=0,(x,y),dp;
+   poly p=((x2+y3)^2+xy6)*((x3+y2)^2+x10y);
+   p=p^2;
+   //timeFactorize(p,2);
+   //timeFactorize(p,20);
+}
+
+proc timeStd(ideal i,list #)
+"USAGE:  timeStd(i,d), i ideal, d integer
+RETURN:  std(i) if the standard basis computation finished after
+         d-1 seconds and i otherwhise
+EXAMPLE: example timeStd; shows an example
+"
+{
+  def P=basering;
+  if (size(#) > 0)
+  {
+    if (system("with", "MP"))
+    {
+      if ((typeof(#[1]) == "int")&&(#[1]))
+      {
+        int wait = #[1];
+        int j = 10;
+
+        string bs = nameof(basering);
+        link l_fork = "MPtcp:fork";
+        open(l_fork);
+        write(l_fork, quote(system("pid")));
+        int pid = read(l_fork);
+        write(l_fork, quote(timeStd(eval(i))));
+
+        // sleep in small intervalls for appr. one second
+        if (wait > 0)
+        {
+          while(j < 1000000)
+          {
+            if (status(l_fork, "read", "ready", j)) {break;}
+            j = j + j;
+          }
+        }
+        j = 1;
+        while (j < wait)
+        {
+          if (status(l_fork, "read", "ready", 1000000)) {break;}
+          j = j + 1;
+        }
+        if (status(l_fork, "read", "ready"))
+        {
+          def result = read(l_fork);
+          if (bs != nameof(basering))
+          {
+            def PP = basering;
+            setring P;
+            def result = imap(PP, result);
+            kill PP;
+          }
+          kill (l_fork);
+        }
+        else
+        {
+          ideal result=i;
+          j = system("sh", "kill " + string(pid));
+        }
+        return (result);
+      }
+    }
+  }
+  return(std(i));
+}
+example
+{ "EXAMPLE:"; echo = 2;
+   ring r=32003,(a,b,c,d,e),dp;
+   int n=6;
+   ideal i=
+   a^n-b^n,
+   b^n-c^n,
+   c^n-d^n,
+   d^n-e^n,
+   a^(n-1)*b+b^(n-1)*c+c^(n-1)*d+d^(n-1)*e+e^(n-1)*a;
+   timeStd(i,2);
+   timeStd(i,20);
+}
+
+proc factorH(poly p)
+"USAGE:  factorH(p)  p poly
+RETURN:  factorize(p)
+NOTE:    changes variables to become the last variable the principal
+         one in the multivariate factorization and factorizes then
+         the polynomial
+EXAMPLE: example factorH; shows an example
+"
+{
+   def R=basering;
+   int i,j;
+   int n=1;
+   int d=nrows(coeffs(p,var(1)));
+   for(i=1;i<=nvars(R);i++)
+   {
+      j=nrows(coeffs(p,var(i)));
+      if(d>j)
+      {
+         n=i;
+         d=j;
+      }
+   }
+   ideal ma=maxideal(1);    //die letzte Variable ist die Hauptvariable
+   ma[nvars(R)]=var(n);
+   ma[n]=var(nvars(R));
+   map phi=R,ma;
+   list fac=factorize(phi(p));
+   list re=phi(fac);
+   return(re);
+}
+example
+{ "EXAMPLE:"; echo = 2;
+  system("random",992851144);
+  ring r=32003,(x,y,z,w,t),lp;
+  poly p=y2w9+yz7t-yz5w4-z2w4t4-w8t3;
+  factorize(p);  //fast
+  system("random",992851262);
+  //factorize(p);  //slow
+  system("random",992851262);
+  factorH(p);
+}