Changeset dd73043 in git for Singular/LIB/rinvar.lib
- Timestamp:
- Jul 18, 2006, 5:22:16 PM (18 years ago)
- Branches:
- (u'spielwiese', '2a584933abf2a2d3082034c7586d38bb6de1a30a')
- Children:
- 731e67e500fa1748d36cc7e4c72bb40cf2ab3b02
- Parents:
- 27b3cfc2e355210dca9a4d1c4b1a6feaed10aca3
- File:
-
- 1 edited
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Singular/LIB/rinvar.lib
r27b3cf rdd73043 1 1 // Last change 10.12.2000 (TB) 2 2 /////////////////////////////////////////////////////////////////////////////// 3 version="$Id: rinvar.lib,v 1.1 5 2006-07-18 11:59:45 Singular Exp $";3 version="$Id: rinvar.lib,v 1.16 2006-07-18 15:22:15 Singular Exp $"; 4 4 category="Invariant theory"; 5 5 info=" … … 7 7 AUTHOR: Thomas Bayer, tbayer@in.tum.de 8 8 http://wwwmayr.informatik.tu-muenchen.de/personen/bayert/ 9 Current Ad ress: Institut fuer Informatik, TU Muenchen9 Current Address: Institut fuer Informatik, TU Muenchen 10 10 OVERVIEW: 11 Implementation based on Derksen's algorithm. Written in the frame of the11 Implementation based on Derksen's algorithm. Written in the scope of the 12 12 diploma thesis (advisor: Prof. Gert-Martin Greuel) 'Computations of moduli 13 13 spaces of semiquasihomogenous singularities and an implementation in Singular' … … 219 219 proc HilbertSeries(ideal I, wt) 220 220 "USAGE: HilbertSeries(I, w); ideal I, intvec wt 221 PURPOSE: compute the polynomial p of the Hilbert Series, represented by p/q, of221 PURPOSE: compute the polynomial p of the Hilbert Series, represented by p/q, of 222 222 the ring K[t_1,...,t_m,y_1,...,y_r]/I1 where 'w' are the weights of 223 223 the variables, computed, e.g., by 'HilbertWeights', 'I1' is of the … … 225 225 RETURN: intvec 226 226 NOTE: the leading 0 of the result does not belong to p, but is needed in 227 the hilbert-driven 'std'.227 the Hilbert driven 'std'. 228 228 " 229 229 { … … 507 507 proc LinearActionQ(Gaction, int nrs) 508 508 "USAGE: LinearActionQ(action,nrs); ideal action, int nrs 509 PURPOSE: check if the action defined by 'action' is linear w.r.t. the variables510 var (nrs + 1...nvars(basering)).509 PURPOSE: check whether the action defined by 'action' is linear w.r.t. the 510 variables var(nrs + 1...nvars(basering)). 511 511 RETURN: 0 action not linear 512 512 1 action is linear … … 550 550 proc LinearCombinationQ(ideal I, poly f) 551 551 "USAGE: LinearCombination(I, f); ideal I, poly f 552 PURPOSE: test iff can be written as a linear combination of the generators of I.552 PURPOSE: test whether f can be written as a linear combination of the generators of I. 553 553 RETURN: 0 f is not a linear combination 554 554 1 f is a linear combination … … 732 732 proc InvariantQ(poly f, ideal G, action) 733 733 "USAGE: InvariantQ(f, G, action); poly f; ideal G, action 734 PURPOSE: check if the polynomial f is invariant w.r.t. Gwhere G acts via734 PURPOSE: check whether the polynomial f is invariant w.r.t. G, where G acts via 735 735 'action' on K^m. 736 736 ASSUME: basering = K[s_1,...,s_m,t_1,...,t_m] where K = Q of K = Q(a) and … … 858 858 'action' is a linear group action of G on K^n (n = ncols(action)) 859 859 RETURN: ideal of the nullcone of G. 860 NOTE: the generators of the nullcone are homogenous, but i .g.not invariant860 NOTE: the generators of the nullcone are homogenous, but in general not invariant 861 861 EXAMPLE: example NullCone; shows an example 862 862 " … … 928 928 proc ReynoldsOperator(ideal Grp, ideal Gaction, list #) 929 929 "USAGE: ReynoldsOperator(G, action [, opt]); ideal G, action; int opt 930 PURPOSE: compute the Reynolds operator of the group G which act via 'action'930 PURPOSE: compute the Reynolds operator of the group G which acts via 'action' 931 931 RETURN: polynomial ring R over a simple extension of the ground field of the 932 932 basering (the extension might be trivial), containing a list … … 1003 1003 proc ReynoldsImage(list reynoldsOp, poly f) 1004 1004 "USAGE: ReynoldsImage(RO, f); list RO, poly f 1005 PURPOSE: compute the Reynolds image of the polynomial f where RO represents1005 PURPOSE: compute the Reynolds image of the polynomial f, where RO represents 1006 1006 the Reynolds operator 1007 1007 RETURN: poly … … 1064 1064 RETURN: list 1065 1065 _[1] ideal I' 1066 _[2] ideal representing a map phi to a ring with probably less vars. s.t .1066 _[2] ideal representing a map phi to a ring with probably less vars. s.th. 1067 1067 phi(I) = I' 1068 1068 _[3] list of variables
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