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BettiDiagram

the diagram of the graded Betti numbers

Syntax
BettiDiagram(X: IDEAL or (quotient)RING or MODULE)

Description
This function computes the ("Macaulay-style") Betti diagram for M .

Example
/**/  use R ::= QQ[t,x,y,z];
/**/  I := ideal(x^2-y*t, x*y-z*t, x*y);
/**/  RES := res(I);
/**/  PrintRes(RES);
0 --> R(-5)^2 --> R(-4)^4 --> R(-2)^3
/**/  B := BettiDiagram(RES);  indent(B);
record[
  Diagram := matrix(ZZ,
 [[3, 0, 0],
  [0, 4, 2]]),
  FirstShift := 2
]
/**/  PrintBettiDiagram(B);
        0    1    2
--------------------
 2:     3    -    -
 3:     -    4    2
--------------------
Tot:    3    4    2

See Also