Changeset fd5013 in git
- Timestamp:
- Aug 2, 2006, 5:40:53 PM (18 years ago)
- Branches:
- (u'spielwiese', '17f1d200f27c5bd38f5dfc6e8a0879242279d1d8')
- Children:
- f6f1dbfc1e8487ccbf1ca0d7a3d2600069315a9f
- Parents:
- d1932987874a4523d2a42efe3046b953ed52af76
- Location:
- Singular/LIB
- Files:
-
- 8 edited
Legend:
- Unmodified
- Added
- Removed
-
Singular/LIB/finvar.lib
rd193298 rfd5013 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id: finvar.lib,v 1.5 0 2006-07-18 15:48:13Singular Exp $"2 version="$Id: finvar.lib,v 1.51 2006-08-02 15:40:47 Singular Exp $" 3 3 category="Invariant theory"; 4 4 info=" … … 138 138 RETURN: a <list>, the first list element will be a gxn <matrix> representing 139 139 the Reynolds operator if we are in the non-modular case; if the 140 characteristic is >0, minpoly==0 and the finite group non-cyclic the140 characteristic is >0, minpoly==0 and the finite group is non-cyclic the 141 141 second list element is an <int> giving the lowest common multiple of 142 142 the matrix group elements' order (used in molien); in general all … … 148 148 (or the generators themselves during the first run). All the ones that 149 149 have been generated before are thrown out and the program terminates 150 when no new elements found in one run. Additionally each time a new150 when no new elements are found in one run. Additionally each time a new 151 151 group element is found the corresponding ring mapping of which the 152 152 Reynolds operator is made up is generated. They are stored in the rows … … 358 358 elements generated by group_reynolds(), lcm is the second return value 359 359 of group_reynolds() 360 RETURN: in case of characteristic 0 a 1x2 <matrix> giving enumerator and360 RETURN: in case of characteristic 0 a 1x2 <matrix> giving numerator and 361 361 denominator of Molien series; in case of prime characteristic a ring 362 362 with the name `ringname` of characteristic 0 is created where the same … … 908 908 new group element is found the corresponding ring mapping of which the 909 909 Reynolds operator is made up is generated. They are stored in the rows 910 of the first return value. In characteristic 0 the term s1/det(1-xE)910 of the first return value. In characteristic 0 the term 1/det(1-xE) 911 911 is computed whenever a new element E is found. In prime characteristic 912 912 a Brauer lift is involved and the terms are only computed after the 913 913 entire matrix group is generated (to avoid the modular case). The 914 returned matrix gives enumerator and denominator of the expanded914 returned matrix gives numerator and denominator of the expanded 915 915 version where common factors have been canceled. 916 916 EXAMPLE: example reynolds_molien; shows an example … … 2064 2064 ASSUME: REY is the first return value of group_reynolds or reynolds_molien and 2065 2065 M the one of molien or the second one of reynolds_molien 2066 DISPLAY: information about the various stages of the program meif v does not2066 DISPLAY: information about the various stages of the program if v does not 2067 2067 equal 0 2068 2068 RETURN: primary invariants (type <matrix>) of the invariant ring … … 2207 2207 ringname gives the name of a ring of characteristic 0 that has been 2208 2208 created by molien or reynolds_molien 2209 DISPLAY: information about the various stages of the program meif v does not2209 DISPLAY: information about the various stages of the program if v does not 2210 2210 equal 0 2211 2211 RETURN: primary invariants (type <matrix>) of the invariant ring … … 2360 2360 <int> 2361 2361 ASSUME: REY is the first return value of group_reynolds or reynolds_molien 2362 DISPLAY: information about the various stages of the program meif v does not2362 DISPLAY: information about the various stages of the program if v does not 2363 2363 equal 0 2364 2364 RETURN: primary invariants (type <matrix>) of the invariant ring and an … … 2503 2503 <int> 2504 2504 ASSUME: REY is the first return value of group_reynolds or reynolds_molien 2505 DISPLAY: information about the various stages of the program meif v does not2505 DISPLAY: information about the various stages of the program if v does not 2506 2506 equal 0 2507 2507 RETURN: primary invariants (type <matrix>) of the invariant ring and an … … 2644 2644 G1,G2,...: <matrices> generating a finite matrix group, v: an optional 2645 2645 <int> 2646 DISPLAY: information about the various stages of the program meif v does not2646 DISPLAY: information about the various stages of the program if v does not 2647 2647 equal 0 2648 2648 RETURN: primary invariants (type <matrix>) of the invariant ring … … 2784 2784 G1,G2,...: <matrices> generating a finite matrix group, flags: an 2785 2785 optional <intvec> with three entries, if the first one equals 0 (also 2786 the default), the program meattempts to compute the Molien series and2787 Reynolds operator, if it equals 1, the program meis told that the2786 the default), the program attempts to compute the Molien series and 2787 Reynolds operator, if it equals 1, the program is told that the 2788 2788 Molien series should not be computed, if it equals -1 characteristic 0 2789 2789 is simulated, i.e. the Molien series is computed as if the base field 2790 2790 were characteristic 0 (the user must choose a field of large prime 2791 characteristic, e.g. 32003) and if the first one is anything else, it2791 characteristic, e.g. 32003), and if the first one is anything else, it 2792 2792 means that the characteristic of the base field divides the group 2793 2793 order, the second component should give the size of intervals between … … 2797 2797 common factors should always be canceled when the expansion is simple 2798 2798 (the root of the extension field occurs not among the coefficients) 2799 DISPLAY: information about the various stages of the program meif the third2799 DISPLAY: information about the various stages of the program if the third 2800 2800 flag does not equal 0 2801 2801 RETURN: primary invariants (type <matrix>) of the invariant ring and if … … 2892 2892 else 2893 2893 { if (v) 2894 { " Since it is impossible for this program meto calculate the Molien series for";2894 { " Since it is impossible for this program to calculate the Molien series for"; 2895 2895 " invariant rings over extension fields of prime characteristic, we have to"; 2896 2896 " continue without it."; … … 3199 3199 ASSUME: REY is the first return value of group_reynolds or reynolds_molien and 3200 3200 M the one of molien or the second one of reynolds_molien 3201 DISPLAY: information about the various stages of the program meif v does not3201 DISPLAY: information about the various stages of the program if v does not 3202 3202 equal 0 3203 3203 RETURN: primary invariants (type <matrix>) of the invariant ring … … 3346 3346 ringname gives the name of a ring of characteristic 0 that has been 3347 3347 created by molien or reynolds_molien 3348 DISPLAY: information about the various stages of the program meif v does not3348 DISPLAY: information about the various stages of the program if v does not 3349 3349 equal 0 3350 3350 RETURN: primary invariants (type <matrix>) of the invariant ring … … 3499 3499 bases elements, v: an optional <int> 3500 3500 ASSUME: REY is the first return value of group_reynolds or reynolds_molien 3501 DISPLAY: information about the various stages of the program meif v does not3501 DISPLAY: information about the various stages of the program if v does not 3502 3502 equal 0 3503 3503 RETURN: primary invariants (type <matrix>) of the invariant ring and an … … 3646 3646 bases elements, v: an optional <int> 3647 3647 ASSUME: REY is the first return value of group_reynolds or reynolds_molien 3648 DISPLAY: information about the various stages of the program meif v does not3648 DISPLAY: information about the various stages of the program if v does not 3649 3649 equal 0 3650 3650 RETURN: primary invariants (type <matrix>) of the invariant ring and an … … 3792 3792 where -|r| to |r| is the range of coefficients of the random 3793 3793 combinations of bases elements, v: an optional <int> 3794 DISPLAY: information about the various stages of the program meif v does not3794 DISPLAY: information about the various stages of the program if v does not 3795 3795 equal 0 3796 3796 RETURN: primary invariants (type <matrix>) of the invariant ring … … 3943 3943 where -|r| to |r| is the range of coefficients of the random 3944 3944 combinations of bases elements, flags: an optional <intvec> with three 3945 entries, if the first one equals 0 (also the default), the program me3945 entries, if the first one equals 0 (also the default), the program 3946 3946 attempts to compute the Molien series and Reynolds operator, if it 3947 equals 1, the program meis told that the Molien series should not be3947 equals 1, the program is told that the Molien series should not be 3948 3948 computed, if it equals -1 characteristic 0 is simulated, i.e. the 3949 3949 Molien series is computed as if the base field were characteristic 0 3950 3950 (the user must choose a field of large prime characteristic, e.g. 3951 32003) and if the first one is anything else, it means that the3951 32003), and if the first one is anything else, it means that the 3952 3952 characteristic of the base field divides the group order, the second 3953 3953 component should give the size of intervals between canceling common … … 3957 3957 always be canceled when the expansion is simple (the root of the 3958 3958 extension field does not occur among the coefficients) 3959 DISPLAY: information about the various stages of the program meif the third3959 DISPLAY: information about the various stages of the program if the third 3960 3960 flag does not equal 0 3961 3961 RETURN: primary invariants (type <matrix>) of the invariant ring and if … … 4060 4060 else 4061 4061 { if (v) 4062 { " Since it is impossible for this program meto calculate the Molien series for";4062 { " Since it is impossible for this program to calculate the Molien series for"; 4063 4063 " invariant rings over extension fields of prime characteristic, we have to"; 4064 4064 " continue without it."; … … 5954 5954 Molien series is computed as if the base field were characteristic 0 5955 5955 (the user must choose a field of large prime characteristic, e.g. 5956 32003) and if the first one is anything else, it means that the5956 32003), and if the first one is anything else, it means that the 5957 5957 characteristic of the base field divides the group order (i.e. it will 5958 5958 not even be attempted to compute the Reynolds operator or Molien … … 6051 6051 else 6052 6052 { if (v) 6053 { " Since it is impossible for this program meto calculate the Molien6053 { " Since it is impossible for this program to calculate the Molien 6054 6054 series for"; 6055 6055 " invariant rings over extension fields of prime characteristic, we … … 6171 6171 i.e. the Molien series is computed as if the base field were 6172 6172 characteristic 0 (the user must choose a field of large prime 6173 characteristic, e.g. 32003) and if the first one is anything else,6173 characteristic, e.g. 32003), and if the first one is anything else, 6174 6174 then the characteristic of the base field divides the group order 6175 6175 (i.e. we will not even attempt to compute the Reynolds operator or … … 6286 6286 else 6287 6287 { if (v) 6288 { " Since it is impossible for this program meto calculate the Molien6288 { " Since it is impossible for this program to calculate the Molien 6289 6289 series for"; 6290 6290 " invariant rings over extension fields of prime characteristic, we … … 6403 6403 THEORY: The ideal of algebraic relations of the invariant ring generators is 6404 6404 calculated, then the variables of the original ring are eliminated and 6405 the polynomials that are left over define the orbit variety 6405 the polynomials that are left over define the orbit variety. 6406 6406 EXAMPLE: example orbit_variety; shows an example 6407 6407 " … … 6620 6620 @* s: a <string> giving a name for a new ring 6621 6621 RETURN: The procedure ends with a new ring named s. 6622 It contains a Groebner basis 6623 (type <ideal>, named G) for the ideal defining the 6624 relative orbit variety with respect to I in the new ring. 6622 It contains a Groebner basis (type <ideal>, named G) for the ideal 6623 defining the relative orbit variety with respect to I in the new ring. 6625 6624 THEORY: A Groebner basis of the ideal of algebraic relations of the invariant 6626 6625 ring generators is calculated, then one of the basis elements plus the … … 6707 6706 @* F: a 1xm <matrix> defining an invariant ring of some matrix group 6708 6707 RETURN: The <ideal> defining the image under that group of the variety defined 6709 by I 6708 by I. 6710 6709 THEORY: rel_orbit_variety(I,F) is called and the newly introduced 6711 6710 @* variables in the output are replaced by the generators of the 6712 6711 @* invariant ring. This ideal in the original variables defines the image 6713 @* of the variety defined by I 6712 @* of the variety defined by I. 6714 6713 EXAMPLE: example image_of_variety; shows an example 6715 6714 " -
Singular/LIB/gmspoly.lib
rd193298 rfd5013 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id: gmspoly.lib,v 1.1 3 2005-05-11 13:02:32Singular Exp $";2 version="$Id: gmspoly.lib,v 1.14 2006-08-02 15:40:50 Singular Exp $"; 3 3 category="Singularities"; 4 4 … … 146 146 attrib(V0,"isSB",1); 147 147 module V1=B; 148 option( "redSB");148 option(redSB); 149 149 while(size(reduce(V1,V0))>0) 150 150 { -
Singular/LIB/gmssing.lib
rd193298 rfd5013 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id: gmssing.lib,v 1. 9 2005-05-18 18:16:32Singular Exp $";2 version="$Id: gmssing.lib,v 1.10 2006-08-02 15:40:50 Singular Exp $"; 3 3 category="Singularities"; 4 4 … … 220 220 RETURN: 221 221 list nf; 222 ideal nf[1]; projection of p to <gmsbasis>C{{s}} mod s^(K+1) 222 ideal nf[1]; projection of p to <gmsbasis>C{{s}} mod s^(K+1) @* 223 223 ideal nf[2]; p==nf[1]+nf[2] 224 NOTE: computation can be continued by setting p =nf[2]224 NOTE: computation can be continued by setting p to nf[2][1] 225 225 EXAMPLE: example gmsnf; shows examples 226 226 " … … 301 301 ideal l[2]; p==matrix(gmsbasis)*l[1]+l[2] 302 302 @end format 303 NOTE: computation can be continued by setting p =l[2]303 NOTE: computation can be continued by setting p to l[2] 304 304 EXAMPLE: example gmscoeffs; shows examples 305 305 " … … 580 580 ASSUME: characteristic 0; local degree ordering; 581 581 isolated critical point 0 of t 582 RETURN: ideal r; roots of the Bernstein polynomial b excluding the root -1 582 RETURN: list: 583 roots of the Bernstein polynomial b (ideal) and its multiplicies 583 584 NOTE: the roots of b are negative rational numbers and -1 is a root of b 584 585 KEYWORDS: Bernstein polynomial … … 1232 1233 proc sppnf(list sp) 1233 1234 "USAGE: sppnf(list(a,w[,m])); ideal a, intvec w, intvec m 1234 ASSUME: ncols( e)==size(w)==size(m)1235 ASSUME: ncols(a)==size(w)==size(m) 1235 1236 RETURN: order (a[i][,w[i]]) with multiplicity m[i] lexicographically 1236 1237 EXAMPLE: example sppnf; shows examples -
Singular/LIB/hnoether.lib
rd193298 rfd5013 1 version="$Id: hnoether.lib,v 1.5 2 2006-07-18 15:48:19Singular Exp $";1 version="$Id: hnoether.lib,v 1.53 2006-08-02 15:40:51 Singular Exp $"; 2 2 category="Singularities"; 3 3 info=" … … 1628 1628 contains the multiplicities of the branches at their infinitely near point 1629 1629 of 0 in its (i-1) order neighbourhood (i.e., i=1: multiplicity of the 1630 branches themselves, i=2: multiplicity of their 1st quadratic transform ed,1630 branches themselves, i=2: multiplicity of their 1st quadratic transform, 1631 1631 etc., @* 1632 1632 Hence, @code{multsequence(INPUT)[1][*,j]} is the multiplicity sequence … … 1788 1788 with: 1789 1789 @code{a_1 , ... , a_n} the sequence of multiplicities of the 1st branch, 1790 @code{[...]} the multiplicities of the j-th transform edof all branches,1790 @code{[...]} the multiplicities of the j-th transform of all branches, 1791 1791 @code{(...)} indicating branches meeting in an infinitely near point. 1792 1792 @end format … … 2242 2242 mu (optional) is Milnor number of f.@* 2243 2243 NP (optional) is output of @code{newtonpoly(f)}. 2244 RETURN: int: 1 if f i nNewton non-degenerate, 0 otherwise.2244 RETURN: int: 1 if f is Newton non-degenerate, 0 otherwise. 2245 2245 SEE ALSO: newtonpoly 2246 2246 KEYWORDS: Newton non-degenerate; Newton polygon … … 4236 4236 RETURN: int, the delta invariant of the singularity at 0, that is, the vector 4237 4237 space dimension of R~/R, (R~ the normalization of the local ring of 4238 the singularity .4238 the singularity). 4239 4239 NOTE: In case the Hamburger-Noether expansion of the curve f is needed 4240 4240 for other purposes as well it is better to calculate this first -
Singular/LIB/qhmoduli.lib
rd193298 rfd5013 39 39 moduli space (note : Spec(R) is the moduli space) 40 40 OPTIONS: 1 compute equations of the mod. space, 41 2 use a primary decomposition 42 4 compute E_f0, i.e., the image of G_f0 43 To combine options, add their value, default: opt =741 2 use a primary decomposition, 42 4 compute E_f0, i.e., the image of G_f0, 43 to combine options, add their value, default: opt =7 44 44 EXAMPLE: example ModEqn; shows an example 45 45 " … … 202 202 if opt = 0, 2, it is the ideal defining the equivariant embedding 203 203 OPTIONS: 1 compute equations of the quotient, 204 2 use a primary decomposition when computing the Reynolds operator 205 To combine options, add their value, default: opt =3.204 2 use a primary decomposition when computing the Reynolds operator,@* 205 to combine options, add their value, default: opt =3. 206 206 EXAMPLE: example QuotientEquations; shows an example 207 207 " … … 410 410 411 411 proc StabOrder(list #) 412 "USAGE: StabOrder(f); poly f ;412 "USAGE: StabOrder(f); poly f 413 413 PURPOSE: compute the order of the stabilizer group of f. 414 414 ASSUME: f quasihomogeneous polynomial with an isolated singularity at 0 … … 433 433 PURPOSE: compute the equations of the isometry group of f. 434 434 ASSUME: f semiquasihomogeneous polynomial with an isolated singularity at 0 435 RETURN: list of two ring 'S1', 'S2'435 RETURN: list of two rings 'S1', 'S2' 436 436 - 'S1' contians the equations of the stabilizer (ideal 'stabid') @* 437 437 - 'S2' contains the action of the stabilizer (ideal 'actionid') … … 469 469 proc StabEqnId(ideal data, intvec wt) 470 470 "USAGE: StabEqn(I, w); I ideal, w intvec 471 PURPOSE: compute the equations of the isometry group of the ideal I 471 PURPOSE: compute the equations of the isometry group of the ideal I, 472 472 each generator of I is fixed by the stabilizer. 473 473 ASSUME: I semiquasihomogeneous ideal wrt 'w' with an isolated singularity at 0 474 RETURN: list of two ring 'S1', 'S2'474 RETURN: list of two rings 'S1', 'S2' 475 475 - 'S1' contians the equations of the stabilizer (ideal 'stabid') @* 476 476 - 'S2' contains the action of the stabilizer (ideal 'actionid') … … 1417 1417 1418 1418 proc Max(data) 1419 "USAGE: Max(data); intvec/list of integers data1419 "USAGE: Max(data); intvec/list of integers 1420 1420 PURPOSE: find the maximal integer contained in 'data' 1421 1421 RETURN: list … … 1431 1431 return(max); 1432 1432 } 1433 example 1434 {"EXAMPLE:"; echo = 2; 1435 Max(list(1,2,3)); 1436 } 1433 1437 1434 1438 /////////////////////////////////////////////////////////////////////////////// 1435 1439 1436 1440 proc Min(data) 1437 "USAGE: Min(data); intvec/list of integers data1441 "USAGE: Min(data); intvec/list of integers 1438 1442 PURPOSE: find the minimal integer contained in 'data' 1439 1443 RETURN: list … … 1449 1453 return(min); 1450 1454 } 1451 1452 /////////////////////////////////////////////////////////////////////////////// 1455 example 1456 {"EXAMPLE:"; echo = 2; 1457 Min(intvec(1,2,3)); 1458 } 1459 1460 /////////////////////////////////////////////////////////////////////////////// -
Singular/LIB/sing.lib
rd193298 rfd5013 1 // $Id: sing.lib,v 1. 29 2005-05-06 14:39:12 hannesExp $1 // $Id: sing.lib,v 1.30 2006-08-02 15:40:52 Singular Exp $ 2 2 //(GMG/BM, last modified 26.06.96) 3 3 /////////////////////////////////////////////////////////////////////////////// 4 version="$Id: sing.lib,v 1. 29 2005-05-06 14:39:12 hannesExp $";4 version="$Id: sing.lib,v 1.30 2006-08-02 15:40:52 Singular Exp $"; 5 5 category="Singularities"; 6 6 info=" … … 182 182 "USAGE: is_reg(f,id); f poly, id ideal or module 183 183 RETURN: 1 if multiplication with f is injective modulo id, 0 otherwise 184 NOTE: let R be the basering and id a submodule of R^n. The procedure checks184 NOTE: Let R be the basering and id a submodule of R^n. The procedure checks 185 185 injectivity of multiplication with f on R^n/id. The basering may be a 186 quotient ring 186 quotient ring. 187 187 EXAMPLE: example is_reg; shows an example 188 188 " … … 214 214 "USAGE: is_regs(i[,id]); i poly, id ideal or module (default: id=0) 215 215 RETURN: 1 if generators of i are a regular sequence modulo id, 0 otherwise 216 NOTE: let R be the basering and id a submodule of R^n. The procedure checks216 NOTE: Let R be the basering and id a submodule of R^n. The procedure checks 217 217 injectivity of multiplication with i[k] on R^n/id+i[1..k-1]. 218 The basering may be a quotient ring 218 The basering may be a quotient ring. 219 219 printlevel >=0: display comments (default) 220 220 printlevel >=1: display comments during computation … … 431 431 432 432 proc qhspectrum (poly f, intvec w) 433 "USAGE: qhspectrum(f,w); f=poly, w=intvec ;433 "USAGE: qhspectrum(f,w); f=poly, w=intvec 434 434 ASSUME: f is a weighted homogeneous isolated singularity w.r.t. the weights 435 435 given by w; w must consist of as many positive integers as there … … 440 440 d = w-degree(f) and si/d = i-th spectral-number(f) 441 441 No return value if basering has parameters or if f is no isolated 442 singularity, displays a warning in this case 442 singularity, displays a warning in this case. 443 443 EXAMPLE: example qhspectrum; shows an example 444 444 " … … 568 568 all relevant information can be obtained. The most important are 569 569 probably vdim(T_1(id)); (which computes the Tjurina number), 570 hilb(T_1(id)); and kbase(T_1(id)) ;571 If T_1 is called with two argument , then matrix([2])*(kbase([1]))570 hilb(T_1(id)); and kbase(T_1(id)). 571 If T_1 is called with two arguments, then matrix([2])*(kbase([1])) 572 572 represents a basis of 1st order semiuniversal deformation of id 573 573 (use proc 'deform', to get this in a direct way). 574 For a complete intersection the proc Tjurina is faster 574 For a complete intersection the proc Tjurina is faster. 575 575 EXAMPLE: example T_1; shows an example 576 576 " … … 653 653 DISPLAY: k-dimension of T_2(id) if printlevel >= 0 (default) 654 654 NOTE: The most important information is probably vdim(T_2(id)). 655 Use proc miniversal to get equations of miniversal deformation.655 Use proc miniversal to get equations of the miniversal deformation. 656 656 EXAMPLE: example T_2; shows an example 657 657 " … … 727 727 DISPLAY: k-dimension of T_1 and T_2 if printlevel >= 0 (default) 728 728 NOTE: Use proc miniversal from deform.lib to get miniversal deformation of i, 729 the list contains all objects used by proc miniversal 729 the list contains all objects used by proc miniversal. 730 730 EXAMPLE: example T_12; shows an example 731 731 " … … 800 800 RETURN: int, which is: 801 801 1. the codimension of id2 in id1, i.e. the vectorspace dimension of 802 id1/id2 if id2 is contained in id1 and if this number is finite 803 2. -1 if the dimension of id1/id2 is infinite 802 id1/id2 if id2 is contained in id1 and if this number is finite@* 803 2. -1 if the dimension of id1/id2 is infinite@* 804 804 3. -2 if id2 is not contained in id1, 805 COMPUTE: consider the two hilberseries iv1(t) and iv2(t), then, in case 1.,805 COMPUTE: consider the two Hilbert series iv1(t) and iv2(t), then, in case 1., 806 806 q(t)=(iv2(t)-iv1(t))/(1-t)^n must be rational, and the result is the 807 807 sum of the coefficients of q(t) (n dimension of basering) … … 933 933 "USAGE: tangentcone(id [,n]); id = ideal, n = int 934 934 RETURN: the tangent cone of id 935 NOTE: the procedure works for any monomial ordering.936 If n=0 use std w.r.t. local ordering ds, if n=1 use locstd 935 NOTE: The procedure works for any monomial ordering. 936 If n=0 use std w.r.t. local ordering ds, if n=1 use locstd. 937 937 EXAMPLE: example tangentcone; shows an example 938 938 " -
Singular/LIB/spcurve.lib
rd193298 rfd5013 1 1 // (anne, last modified 31.5.99) 2 2 ///////////////////////////////////////////////////////////////////////////// 3 version="$Id: spcurve.lib,v 1.2 0 2005-05-06 14:39:18 hannesExp $";3 version="$Id: spcurve.lib,v 1.21 2006-08-02 15:40:53 Singular Exp $"; 4 4 category="Singularities"; 5 5 info=" … … 274 274 "USAGE: discr(sem,n); sem ideal, n integer 275 275 ASSUME: sem is the versal deformation of an ideal of codimension 2. @* 276 the first n variables of the ring are treated as variables277 all the others as parameters 276 The first n variables of the ring are treated as variables 277 all the others as parameters. 278 278 RETURN: ideal describing the discriminant 279 279 NOTE: This is not a powerful algorithm! -
Singular/LIB/spectrum.lib
rd193298 rfd5013 1 1 /////////////////////////////////////////////////////////////////////////////// 2 version="$Id: spectrum.lib,v 1.1 8 2003-05-30 09:49:37 mschulzeExp $";2 version="$Id: spectrum.lib,v 1.19 2006-08-02 15:40:53 Singular Exp $"; 3 3 category="Singularities"; 4 4 info=" … … 54 54 ring R=0,(x,y),ds; 55 55 poly f=x^31+x^6*y^7+x^2*y^12+x^13*y^2+y^29; 56 spectrumnd(f); 56 list s=spectrumnd(f); 57 size(s[1]); 58 s[1][22]; 59 s[2][22]; 57 60 } 58 61 ///////////////////////////////////////////////////////////////////////////////
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