Changeset e9f5b2 in git for Singular/LIB/ncdecomp.lib

Timestamp:

Jul 7, 2009, 6:29:58 PM (15 years ago)

Author:

Viktor Levandovskyy <levandov@…>

Branches:

(u'spielwiese', 'fe61d9c35bf7c61f2b6cbf1b56e25e2f08d536cc')

Children:

642e65dac97b59e7fbbbcd4fa0e29e65a4ae0853

Parents:

6d5f07fc0cb4ce2f4c48acf8a4816a6c809a5175

Message:

*levandov: documentation and assumptions reworked


git-svn-id: file:///usr/local/Singular/svn/trunk@11956 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• Singular/LIB/ncdecomp.lib (modified) (9 diffs)

Singular/LIB/ncdecomp.lib

@@ -1 +1 @@
 ///////////////////////////////////////////////////////////////////////////////
-version="$Id: ncdecomp.lib,v 1.14 2009-04-09 12:04:42 seelisch Exp $";
+version="$Id: ncdecomp.lib,v 1.15 2009-07-07 16:29:58 levandov Exp $";
 category="Noncommutative";
 info="
@@ -7 +7 @@
 
 OVERVIEW:
-This library presents algorithms for the  central character
-decomposition of a module, i.e. a decomposition into generalized weight modules with respect to the center. Based on ideas of O. Khomenko and V. Levandovskyy (see the article [L2] in the References for details).
+@* This library presents algorithms for the central character decomposition of a module, 
+@* i.e. a decomposition into generalized weight modules with respect to the center. 
+@* Based on ideas of O. Khomenko and V. Levandovskyy (see the article [L2] in the 
+@* References for details).
 
 PROCEDURES:
@@ -19 +21 @@
   LIB "ncalg.lib";
   LIB "primdec.lib";
-///////////////////////////////////////////////////////////////////////////////
+  LIB "central.lib";
+
+///////////////////////////////////////////////////////////////////////////////
+
+proc testncdecomplib()
+{
+  example CentralQuot;
+  example CentralSaturation;
+  example CenCharDec;
+  example IntersectWithSub;
+}
+
 static proc CharKernel(list L, int i)
 {
@@ -106 +119 @@
 RETURN:  module
 PURPOSE: compute the central quotient M:G
-THEORY:  for an ideal G of the center of an algebra and a submodule M of A^n, the central quotient of M by G is defined to be
+THEORY:  for an ideal G of the center of an algebra and a submodule M of A^n, 
+@* the central quotient of M by G is defined to be
 @* M:G  :=  { v in A^n | z*v in M, for all z in G }.
 NOTE:    the output module is not necessarily given in a Groebner basis
@@ -112 +126 @@
 EXAMPLE: example CentralQuot; shows examples
 "{
+/* check assupmtion. Elt's of G must be central */
+  if (! inCenter(G) )
+  {
+    ERROR("ideal in the 2nd argument is not in the center of the base ring!");
+  }
   int i;
   list @L;
@@ -147 +166 @@
 EXAMPLE: example CentralSaturation; shows examples
 "{
+/* check assupmtion. Elt's of T must be central */
+  if (! inCenter(T) )
+  {
+    ERROR("ideal in the 2nd argument is not in the center of the base ring!");
+  }
   option(redSB);
   option(redTail);
@@ -209 +233 @@
     Center = #;
   }
+
+/* check assupmtion. Elt's of G must be central */
+  if (! inCenter(Center) )
+  {
+    ERROR("ideal in the 2nd argument is not in the center of the base ring!");
+  }
+
 // M = A/I
 //1. Find the Zariski closure of Supp_Z M
@@ -335 +366 @@
 "USAGE:  IntersectWithSub(M,Z),  M an ideal, Z an ideal
 ASSUME: Z consists of pairwise commutative elements
-RETURN:  ideal, of two-sided generators, not a Groebner basis
+RETURN:  ideal of two-sided generators, not a Groebner basis
 PURPOSE: computes the intersection of M with the subalgebra, generated by Z
 NOTE:    usually Z consists of generators of the center
@@ -358 +389 @@
   }
   // returns a submodule of M, equal to M \cap Z
-  // correctness: Z should consists of pairwise
+  // assume/correctness: Z should consists of pairwise
   // commutative elements
   int nz = size(Z);