2016-05-07 12:46:28 -0600 received badge ● Popular Question (source) 2014-09-05 15:49:42 -0600 received badge ● Editor (source) 2014-09-05 15:49:05 -0600 asked a question Problems with heft vectors in M2 I hope this question is on-topic on this forum. I am working with the "NormalToricVarieties" package in M2. Part of my research involves determining when the higher cohomology groups of certain twists of the structure sheaf of a toric variety vanish. I have a specific example where in computing HH^1(X,OO_X(1,1)) I am confronted with the following error: stdio:8:3:(3): error: heft vector required that is positive on the degrees of the variables {0, 1, 2, 3, 4, 5, 6} I know that this group should be trivial but somehow the absence of a heft vector is bothering the compiler. I'm not sure whether or not there is a way to get M2 to compute this group. Does anyone happen to know of any workarounds in this situation? The example I am using is as follows: loadPackage "NormalToricVarieties"; Rho = { { 0 , 0 , 0 , 0 , 1 } , { 1 , 0 , 0 , 0 , 1 } , { 0 , 1 , 0 , 0 , 1 } , { 0 , 0 , 1 , 0 , 1 } , { 0 , 0 , 0 , 1 , 1 } , { -1 , -2 , -1 , -1 , 1 } , { -2 , -1 , -1 , -1 , 1 } }; Sigma = { { 2 , 3 , 4 , 5 , 6 } , { 0 , 1 , 2 , 3 , 4 } , { 0 , 1 , 2 , 3 , 5 } , { 0 , 1 , 2 , 4 , 5 } , { 0 , 1 , 3 , 4 , 5 } , { 0 , 2 , 3 , 4 , 5 } }; X = normalToricVariety(Rho,Sigma); HH^2(X,OO_X(1,1)) -- HH^n for n=2 works fine HH^1(X,OO_X(1,1)) -- HH^n for n=1 gives an error