Changeset 823679 in git for Singular/LIB/schubert.lib

Timestamp:

Nov 7, 2013, 10:42:07 AM (9 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

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

Children:

a97ac01c3b64767f26ac2bbccd84652d536f371ddcd92ddcba49d3aa5461148604e8d6f4e99d4625

Parents:

2fa80a36c041e00aa30582d92c55f22cc3fe47d8

git-author:

Hans Schoenemann <hannes@mathematik.uni-kl.de>2013-11-07 10:42:07+01:00

git-committer:

Hans Schoenemann <hannes@mathematik.uni-kl.de>2013-11-07 10:42:48+01:00

Message:

chg: new schubert.lib (using parallel.lib)

File:

• Singular/LIB/schubert.lib (modified) (6 diffs)

Singular/LIB/schubert.lib

@@ -88 +88 @@
                                         corresponding the number of rational
                                         curves on a general Calabi-Yau threefold
+    sumofquotients(stack,list)          prepare a command for parallel
+                                        computation
     part(poly,int)                      compute a homogeneous component of a
                                         polynomial.
@@ -109 +111 @@
 LIB "general.lib";
 LIB "homolog.lib";
+LIB "parallel.lib";
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -844 +847 @@
 }
 
+proc sumofquotients(stack M, list F, list #)
+"USAGE:     sumofquotient(M,F,#); M stack, F list, # list
+RETURN:     number
+THEORY:     This is useful for the parallel computation of rationalCurve.
+KEYWORDS:   Gromov-Witten invariants, rational curves on Calabi-Yau threefolds
+EXAMPLE:    example sumofquotients; shows an example
+"
+{
+    if (size(#) == 0) {list l = 5;}
+    else {list l = #;}
+    number sum = 0;
+    number s, t;
+    int i,j;
+    for (i = size(F); i > 0; i--)
+    {
+        s = 1;
+        for (j=1;j<=size(l);j++)
+        {
+            s = s*contributionBundle(M,F[i][1],list(l[j]));
+        }
+        t = F[i][2]*normalBundle(M,F[i][1]);
+        sum = sum + s/t;
+    }
+    return(sum);
+}
+example
+{
+    "EXAMPLE:"; echo=2;
+    ring r = 0,x,dp;
+    variety P = projectiveSpace(4);
+    stack M = moduliSpace(P,2);
+    list F = fixedPoints(M);
+    sumofquotients(M,F);
+    sumofquotients(M,F,list(5));
+}
+
 proc rationalCurve(int d, list #)
 "USAGE:     rationalCurve(d,#); d int, # list
@@ -856 +895 @@
     def R = basering;
     setring R;
-    int n,i,j;
+    int n,i;
     if (size(#) == 0) {n = 4; list l = 5;}
     else {n = size(#)+3; list l = #;}
@@ -862 +901 @@
     stack M = moduliSpace(P,d);
     def F = fixedPoints(M);
+    int ncpus = system("cpu");
+    int sizeF = size(F);
+    list args;
+    int from = 1;
+    int to;
+    for (i = 1; i <= ncpus; i++)
+    {
+        to = (sizeF*i) div ncpus;
+        args[i] = list(M, list(F[from..to]), l);
+        from = to+1;
+    }
+    list results = parallelWaitAll("sumofquotients", args);
     number r = 0;
-    for (i=1;i<=size(F);i++)
-    {
-        graph G = F[i][1];
-        number s = 1;
-        for (j=1;j<=size(l);j++)
-        {
-            s = s*contributionBundle(M,G,list(l[j]));
-        }
-        number t = F[i][2]*normalBundle(M,G);
-        r = r + s/t;
-        kill s,t,G;
+    for (i = 1; i <= ncpus; i++)
+    {
+        r = r + results[i];
     }
     return (r);
@@ -902 +945 @@
     rationalCurve(4,list(3,2,2));
     rationalCurve(4,list(2,2,2,2));
+    */
 }