Singular

D.6.16.8 posweight

Procedure from library `spcurve.lib` (see spcurve_lib).

Usage:
posweight(M,t1,n[,s]); M matrix, t1 module, n int, s string
n=0 : all deformations of non-negative weight
n=1 : only non-constant deformations of non-negative weight
n=2 : all deformations of positive weight

Assume:
M is a presentation matrix of a Cohen-Macaulay codimension 2 ideal and t1 is its T1 space in matrix notation

Return:
new ring containing a list posw, consisting of a presentation matrix describing the deformation given by the generators of T1 of non-negative/positive weight and the weight vector for the new variables

Note:
The current basering should not contain any variables named T(i) where i is some integer!

Example:
 ```LIB "spcurve.lib"; ring r=32003,(x(1),x(2),x(3)),ds; ideal curve=(x(3)-x(1)^2)*x(3),(x(3)-x(1)^2)*x(2),x(2)^2-x(1)^7*x(3); matrix M=isCMcod2(curve); list l=matrixT1(M,3); def rneu=posweight(l[1],std(l[2]),0); setring rneu; pmat(posw[1]); ==> T(2)+x(1)*T(1), -x(3)+x(1)^2, ==> -x(3), x(2), ==> x(2), -x(1)^7 posw[2]; ==> 3,1 ```