CoCoA:BettiMatrix

BettiMatrix

the matrix of the graded Betti numbers

Description

This function returns the Betti matrix for M.

Example

  Use R ::= Q[t,x,y,z];
  I := Ideal(x^2-yt,xy-zt,xy);
  Res(I);
0 --> R^2(-5) --> R^4(-4) --> R^3(-2)
-------------------------------
  BettiMatrix(I);
--------------

--------------
   0    0    0
   0    0    3
   0    0    0
   0    4    0
   2    0    0
--------------

-------------------------------
  Untagged(BettiMatrix(I));
Mat([
  [0, 0, 0],
  [0, 0, 3],
  [0, 0, 0],
  [0, 4, 0],
  [2, 0, 0]
])
-------------------------------

Syntax

BettiMatrix(M:IDEAL or MODULE):TAGGED(<quotes>$io.Matrix</quotes>)

Res

GB.GetBettiMatrix

BettiDiagram

   <type>groebner</type>
   <type>ideal</type>
   <type>module</type>