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D.15.13.36 areZeroElements
Procedure from library multigrading.lib (see multigrading_lib).
- Usage:
- areZeroElements(D, [T]); intmat D, group T
- Purpose:
- For a integer matrix D, considered column-wise as a set of
integer vecors representing the multidegree of some polynomial
or vector this method checks whether all these multidegrees
are contained in the grading group
group (either set globally or given as an optional argument),
i.e. if they all are zero in the multigrading.
Example:
| | LIB "multigrading.lib";
ring r = 0,(x,y,z),dp;
intmat S[2][3]=
1,0,1,
0,1,1;
intmat L[2][1]=
2,
2;
setBaseMultigrading(S,L);
poly a = 1;
poly b = xyz;
ideal I = a, b;
print(multiDeg(I));
==> 0 2
==> 0 2
intmat m[5][2]=multiDeg(a),multiDeg(b); m=transpose(m);
print(multiDeg(a));
==> 0,
==> 0
print(multiDeg(b));
==> 2,
==> 2
print(m);
==> 0 2 0 0 0
==> 0 2 0 0 0
areZeroElements(m);
==> 1
intmat LL[2][1]=
1,
-1;
areZeroElements(m,LL);
==> 0
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