getDiagonalEntries -- extracts a list of diagonal entries for a GrothendieckWittClass

• Usage:

  getDiagonalEntries beta

• Inputs:
  • beta, a Grothendieck-Witt Class, over a field or finite étale algebra over a field
• Outputs:
  • L, a list, of elements $a_i$ of the field or finite étale algebra over a field, where $i = 1,\dots,n $, such that $\beta \cong \langle a_1,\ldots,a_n\rangle$

i1 : beta = makeGWClass matrix(QQ, {{3,0,0},{0,2,0},{0,0,7}});

i2 : getDiagonalEntries beta

o2 = {3, 2, 7}

o2 : List

i3 : gamma = makeGWClass matrix(RR, {{0,0,1},{0,1,0},{1,0,0}});

i4 : getDiagonalEntries gamma

o4 = {2, 1, -.5}

o4 : List