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NumericalSchubertCalculus :: bracket2partition

bracket2partition -- dictionary between different notations for Schubert conditions.

Synopsis

Description

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

See also

Ways to use bracket2partition :