BettiDiagram -- the diagram of the graded Betti numbers |
Syntax |
BettiDiagram(X: IDEAL or (quotient)RING or MODULE) |
Description |
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 |