numgens(Ideal) -- number of generators of an ideal

Synopsis

• Function: numgens

• Usage:

  numgens I

• Inputs:
  • I, an ideal
• Outputs:
  • an integer, number of generators of I

Description

i1 : R = QQ[a..d];

i2 : I = ideal(a^2-b*d, a^2-b*d, c^2, d^2);

o2 : Ideal of R

i3 : numgens I

o3 = 4

In order to find a more efficient set of of generators, use mingens or trim.

i4 : mingens I

o4 = | d2 c2 a2-bd |

             1       3
o4 : Matrix R  <--- R

i5 : numgens trim I

o5 = 3

See also

• mingens -- minimal generator matrix
• trim -- minimize generators and relations
• generators -- provide matrix or list of generators