A Schubert condition in the Grassmannian Gr(k,n) is encoded either by a partition l or by a bracket b.
A partition is a weakly decreasing list of at most k nonnegative integers less than or equal to n-k. It may be padded with zeroes to be of length k.
A bracket is a strictly increasing list of length k of positive integers between 1 and n.
This function writes a bracket as a partition. They are related as follows bk+1-i=n-i-li, for i=1,...,k.
i1 : b = {1,3}; |
i2 : n = 4; |
i3 : bracket2partition(b,n) o3 = {2, 1} o3 : List |
i4 : n = 6; |
i5 : bracket2partition(b,n) o5 = {4, 3} o5 : List |
i6 : b = {2,4,6}; |
i7 : bracket2partition(b,n) o7 = {2, 1, 0} o7 : List |